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#26 2011-05-19 08:22:08

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,562

Re: Let's make triangular numbers.

351
   a triangle with 26 rows, pair them up for 13 pairs of 27.
270 + 81 = 351, yup.


igloo myrtilles fourmis

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#27 2011-05-19 14:41:09

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

378

Is the sum of two other traingular numbers.

378 = Triangular(12) + Triangular(24)


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#28 2011-05-25 00:02:10

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,395

Re: Let's make triangular numbers.

I see what you’re up to here.

Everyone is holding off from posting because you all want to hit post #31.

So I’m going to have it this way.

The North Circular Road around  inner London = 406

Bob

smile


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#29 2011-05-25 00:04:40

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,395

Re: Let's make triangular numbers.

Then

(root(4) x 10 + (4 + 5)) x 3 x 5 = 435

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#30 2011-05-25 00:06:44

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,395

Re: Let's make triangular numbers.

Triangular  45 with a triangular 6 between = 465

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#31 2011-05-25 00:08:01

bob bundy
Moderator
Registered: 2010-06-20
Posts: 6,395

Re: Let's make triangular numbers.

roflol roflol roflol


496  Arrrrhh!  That’s perfect!

Bob


You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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#32 2011-05-25 02:56:40

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

528

2^9 + 2^4 = 528


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#33 2011-05-25 08:29:05

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

561

if HCF(561,b)=1 then b^560 is congruent to 1 modulo 561

Last edited by anonimnystefy (2011-08-14 22:39:57)


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#34 2011-05-25 09:10:04

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

595



In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#35 2011-05-25 09:15:28

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

630=2*3*3*5*7=97+101+103+107+109+113 which are consecutive primes


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#36 2011-05-25 09:50:48

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

666

The mark of the beast.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#37 2011-05-25 22:19:21

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

703-a Kaprekar number

Last edited by anonimnystefy (2011-05-25 22:22:06)


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#38 2011-08-14 09:28:39

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

740-a non-totient number


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#39 2011-08-14 18:34:26

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

Hi;

741 a triangular number.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#40 2011-08-14 22:34:40

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

oh yes you are right

catching up:
780-also a hexagonal number,Harshad number,sum of ten consecutive primes:

780=59 + 61 + 67 + 71 + 73 + 79 + 83 + 89 + 97 + 101


820-Harshad number:

8+2+0|820


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#41 2012-07-04 04:58:55

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,562

Re: Let's make triangular numbers.

861 = 41 + 820

  41 by 21 = 800 + 1 + 40 + 20


igloo myrtilles fourmis

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#42 2012-07-04 05:24:12

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

Hi;

903 not a prime.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#43 2012-07-04 05:27:26

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

946-not a prime either.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#44 2012-07-04 05:29:22

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

990 almost a prime.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#45 2012-07-04 05:33:24

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

1035-first triangular number greater than 1000.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#46 2012-07-04 05:36:30

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

1081 also not a prime.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#47 2012-07-04 05:40:46

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,532

Re: Let's make triangular numbers.

1128-not not a not-prime


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#48 2012-07-04 05:42:33

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

1176 add 600 and it has meaning today!


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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#49 2012-12-13 18:10:59

mathaholic
Member
From: Juliania
Registered: 2012-11-29
Posts: 2,845
Website

Re: Let's make triangular numbers.


"Double the fun, double the thrill, double the coolness" - Julianthewiki

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#50 2012-12-13 20:44:41

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,776

Re: Let's make triangular numbers.

The next triangular number is 1275.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

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