Is this cool with you?

gAr · 2012-03-04 01:17:47

Hi,

Okay.

bobbym · 2012-03-04 01:24:31

Hi gAr;

If you have some time could you show how you set the initial conditions for the recurrence.

gAr · 2012-03-04 01:50:05

Hi bobbym,

Initial conditions can be easily derived by casework, but when I check for f(1,1,1,1), I get 23 if I set f(0,0,0,0)=1.
But I get right answers when I start from higher values.

bobbym · 2012-03-04 01:53:21

Hi gAr;

Okay, thank you.

gAr · 2012-03-04 02:05:07

Hi bobbym,

Did you also try the recurrence?

bobbym · 2012-03-04 02:07:37

Hi gAr;

No I did not. I prefer this method.

gAr · 2012-03-04 02:10:14

Me too.
And I think we may be able to deduce the g.f from this.

bobbym · 2012-03-04 02:12:04

That is what I was hoping but putting that expanded answer back into a rational function of 4 variables has not been easy.

gAr · 2012-03-04 02:48:01

Yeah, it's not so easy.

bobbym · 2012-03-04 02:52:23

Even multivariable gf's with just 2 variables are only partially understood. For 3 or 4 variables...

anonimnystefy · 2012-03-04 20:51:33

Hi guys

One question...What's the main purpose of generating functions?

bobbym · 2012-03-04 23:12:54

They sum series, they test for unimodality, they get means, standard deviations and higher moments, they convert counting problems into algebraic ones...

anonimnystefy · 2012-03-04 23:58:42

Hi bobbym

Those are the uses.But why were they created in the first place?

bobbym · 2012-03-05 00:02:36

I think it was DeMoivre who first noticed that counting problems and polynomial multiplication were the same thing.

anonimnystefy · 2012-03-05 00:16:16

Smart fellow, indeed.

bobbym · 2012-03-05 00:18:40

He was a friend of Isaac Newton who would throw customers his way.

anonimnystefy · 2012-03-05 00:29:37

Good fellow as well.

bobbym · 2012-03-05 00:32:05

Newton must have thought highly of him to overlook his French ancestry.

anonimnystefy · 2012-03-05 00:44:44

Obviously.While we are at famous mathematicians, I must say that of all of them Fermat annoys me the most.

bobbym · 2012-03-05 00:46:56

Maybe because he was not a mathematician!

anonimnystefy · 2012-03-05 01:15:34

He wasn't?

bobbym · 2012-03-05 03:29:27

No he was an amateur mathematician. He was a lawyer and town magistrate by profession.

anonimnystefy · 2012-03-05 08:05:09

That explains a lot.

bobbym · 2012-03-05 08:17:32

As a lawyer and judge he was ordinary. When pursuing his hobby he was incredible.

anonimnystefy · 2012-03-05 08:30:06

I don't like him as a mathematician.

Math Is Fun Forum

#1351 2012-03-04 01:17:47

Re: Is this cool with you?

#1352 2012-03-04 01:24:31

Re: Is this cool with you?

#1353 2012-03-04 01:50:05

Re: Is this cool with you?

#1354 2012-03-04 01:53:21

Re: Is this cool with you?

#1355 2012-03-04 02:05:07

Re: Is this cool with you?

#1356 2012-03-04 02:07:37

Re: Is this cool with you?

#1357 2012-03-04 02:10:14

Re: Is this cool with you?

#1358 2012-03-04 02:12:04

Re: Is this cool with you?

#1359 2012-03-04 02:48:01

Re: Is this cool with you?

#1360 2012-03-04 02:52:23

Re: Is this cool with you?

#1361 2012-03-04 20:51:33

Re: Is this cool with you?

#1362 2012-03-04 23:12:54

Re: Is this cool with you?

#1363 2012-03-04 23:58:42

Re: Is this cool with you?

#1364 2012-03-05 00:02:36

Re: Is this cool with you?

#1365 2012-03-05 00:16:16

Re: Is this cool with you?

#1366 2012-03-05 00:18:40

Re: Is this cool with you?

#1367 2012-03-05 00:29:37

Re: Is this cool with you?

#1368 2012-03-05 00:32:05

Re: Is this cool with you?

#1369 2012-03-05 00:44:44

Re: Is this cool with you?

#1370 2012-03-05 00:46:56

Re: Is this cool with you?

#1371 2012-03-05 01:15:34

Re: Is this cool with you?

#1372 2012-03-05 03:29:27

Re: Is this cool with you?

#1373 2012-03-05 08:05:09

Re: Is this cool with you?

#1374 2012-03-05 08:17:32

Re: Is this cool with you?

#1375 2012-03-05 08:30:06

Re: Is this cool with you?

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