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Search: id:A088692
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A088692 E.g.f: A(x) = f(x*A(x)), where f(x)=(1+2*x)*exp(x). +0
3
1, 3, 23, 304, 5829, 147696, 4670371, 177383424, 7874174601, 400298556160, 22940919680271, 1463679309053952, 102911522568495757, 7906731860604186624, 659108356837269579675, 59252790438687592677376 (list; graph; listen)
OFFSET

0,2

COMMENT

Radius of convergence of A(x): r = (1/4)*exp(-1/2) = 0.151632.., where A(r) = 2*exp(1/2), and r = limit a(n)/a(n+1)*n as n->infinity.

FORMULA

a(n) equals the coefficient of x^n in ((1+2*x)*exp(x))^(n+1)/(n+1).

a(n) = Sum_{k=1..n} 2^(n-k)*n^(k-2)*n!/k!*binomial(n-1,k-1) (offset 1). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jun 19 2006

PROGRAM

(PARI) a(n)=n!*polcoeff(((1+2*x)*exp(x))^(n+1)+x*O(x^n), n, x)/(n+1)

CROSSREFS

Cf. A088690, A088693.

Sequence in context: A006555 A060090 A052842 this_sequence A129458 A118184 A027486

Adjacent sequences: A088689 A088690 A088691 this_sequence A088693 A088694 A088695

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Oct 07 2003

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Last modified November 21 14:49 EST 2008. Contains 150807 sequences.


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