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#1 2006-06-16 04:40:06
- pal2006
- Guest
fill the series
2,3,10,39,172,?
what will be the next no.?and how?
#2 2006-06-16 04:57:55
- luca-deltodesco
- Member
- Registered: 2006-05-05
- Posts: 1,470
Re: fill the series
2,3,10,39,172,?
what will be the next no.?and how?
ive tried loads of things, but im stumped
The Beginning Of All Things To End.
The End Of All Things To Come.
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#3 2006-06-16 05:30:44
- Ricky
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- Registered: 2005-12-04
- Posts: 3,791
Re: fill the series
And so is the online encyclopedia of integer sequences. Where is this sequence coming from? A math textbook? A teacher? You just put a bunch of numbers next to each other?
"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."
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#4 2006-06-16 06:52:22
- pal2006
- Guest
Re: fill the series
This Question Is From One Of The Question Banks Of M.b.a
#5 2006-06-16 11:57:09
- MathsIsFun
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- Registered: 2005-01-21
- Posts: 7,713
Re: fill the series
Maybe not an integer sequence ... could be real numbers and the sequence is exponential.
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
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#6 2006-06-16 14:25:48
- Ricky
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- Registered: 2005-12-04
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Re: fill the series
Huh? All of the numbers given are integers. Are you suggesting the numbers on down the line can be decimals?
"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."
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#7 2006-06-18 01:03:49
- jukka
- Guest
Re: fill the series
The answer is veeeeery logical and in my opinion very simple... You just have to see those numbers in a different way,
If u still havent found what u are looking for:
SPOILER!!!
Try to add two of numbers with eachother...
#8 2006-06-18 02:42:19
- numen
- Member
- Registered: 2006-05-03
- Posts: 115
Re: fill the series
jukka, I thought I had it too. But it doesn't work with the last number 172, I get it to something else 
am I missing something?
Edit: Nevermind, I got it now 
Last edited by numen (2006-06-18 03:00:45)
Bang postponed. Not big enough. Reboot.
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#9 2006-06-18 04:58:59
- luca-deltodesco
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- Registered: 2006-05-05
- Posts: 1,470
Re: fill the series
jukka, I thought I had it too. But it doesn't work with the last number 172, I get it to something else
Edit: Nevermind, I got it now
well i dunno about the nevermind, but when i first posted, i thought i had got it with adding the numbers via
u[n] = (n-1)(u[n-1]+u[n-2])
i.e
u[3] = 2*(2+3) = 10
u[4] = 3*(10+3) = 39
u[5] = 4*(39+10) = 186 =/= 172, and then i realised it was wrong
so what is the answer
The Beginning Of All Things To End.
The End Of All Things To Come.
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#10 2006-06-18 07:38:03
- numen
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- Registered: 2006-05-03
- Posts: 115
Re: fill the series
Bang postponed. Not big enough. Reboot.
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