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Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 181
Location: Hong Kong
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Posted: Mon Oct 25, 2004 7:27 pm Post subject: Recurrence relation
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Consider a recurrence satisfying T1=1, and Tn=T1T_(n-1)+T2T_(n-2)+…+T_(n-1)T1 I consider f(x)=T1x+T2x^2+…. (suppose f(x) is convergent) then i get f(x)^2 = f(x)-x f(x) = [1-sqrt(1-4x)]/2.
But then how to find out the general term of T_n?
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Kenny TM~
Frequent VisitorJoined: 20 Jan 2004Posts: 127
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Posted: Tue Oct 26, 2004 7:14 pm Post subject: Re: Recurrence relation
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Soarer wrote:
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Consider a recurrence satisfying T1=1, and Tn=T1T_(n-1)+T2T_(n-2)+…+T_(n-1)T1 I consider f(x)=T1x+T2x^2+…. (suppose f(x) is convergent) then i get f(x)^2 = f(x)-x f(x) = [1-sqrt(1-4x)]/2.
But then how to find out the general term of T_n?
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This would be useful: http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cgi?Anum=A000108
Edit:
Since f is a g.f. of , we could use the binomial expansion of to get the coefficients of each term.
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Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 181
Location: Hong Kong
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Posted: Tue Oct 26, 2004 7:49 pm Post subject:
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Thanks
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Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 181
Location: Hong Kong
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Posted: Tue Oct 26, 2004 9:17 pm Post subject:
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How about a variation?
Tn=T0T_(n-1)+T1T_(n-2)+…+T_(n-1)T0
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Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 181
Location: Hong Kong
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Posted: Tue Oct 26, 2004 9:19 pm Post subject: Re: Recurrence relation
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Kenny TM~ wrote:
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Soarer wrote:
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Consider a recurrence satisfying T1=1, and Tn=T1T_(n-1)+T2T_(n-2)+…+T_(n-1)T1 I consider f(x)=T1x+T2x^2+…. (suppose f(x) is convergent) then i get f(x)^2 = f(x)-x f(x) = [1-sqrt(1-4x)]/2.
But then how to find out the general term of T_n?
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This would be useful: http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cgi?Anum=A000108
Edit:
Since f is a g.f. of , we could use the binomial expansion of to get the coefficients of each term.
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may i know what does the binonmial theorem with non-integer power look like?
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Kenny TM~
Frequent VisitorJoined: 20 Jan 2004Posts: 127
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Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 181
Location: Hong Kong
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Posted: Wed Oct 27, 2004 7:08 pm Post subject:
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Let’s say T0=1. For taylor’s series, do you mean using this formula,
f(x)=f(0)+f'(0)x+f”(0)x^2+… and so on?
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Kenny TM~
Frequent VisitorJoined: 20 Jan 2004Posts: 127
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Posted: Thu Oct 28, 2004 7:30 pm Post subject:
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Soarer wrote:
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Let’s say T0=1. For taylor’s series, do you mean using this formula,
f(x)=f(0)+f'(0)x+f”(0)x^2+… and so on?
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It is
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If we define , then T’ would be same as the original T.
BTW, if (in the original def.) , then . (C(n) is the function described in here)
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Also, we can define the binomial coefficent for natural k as (not using Gamma function):
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Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 181
Location: Hong Kong
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Posted: Thu Oct 28, 2004 9:04 pm Post subject:
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ah yes…. i typed taylor’s formula wrongly…. missing out all those factorials in the denominator.. sorry.
Thanks anyway.
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Polam
Frequent VisitorJoined: 03 Nov 2003Posts: 333
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Posted: Thu Oct 28, 2004 9:50 pm Post subject:
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This is very interesting. I was working on the following:
with , , and
with . Is there anything that you can say about them?
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