A113327 - OEIS

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A113327

a(n) = Sum_{k=0..n} 2^k*A111146(n,k).

1, 2, 8, 36, 176, 928, 5296, 33024, 227776, 1757504, 15269888, 149327616, 1632715520, 19758502912, 261836047360, 3763432774656, 58208166178816, 962637398577152, 16934963591229440, 315578267054112768

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..19.

FORMULA

G.f.: A(x) = 1/(1 - 2*x*Sum_{k>=0} (k+1)!*x^k ).

EXAMPLE

A(x) = (1 + 2*x + 8*x^2 + 36*x^3 + 176*x^4 + 928*x^5 +..) =

1/(1 - 2/1!*x*(1! + 2!*x + 3!*x^2 + 4!*x^3 + 5!*x^4 +..) ).

PROG

(PARI) {a(n)=local(y=2, x=X+X*O(X^n)); polcoeff(1/(1 - y/(y-1)!*x*sum(k=0, n, (y-1+k)!*x^k)), n, X)}

CROSSREFS

Cf. A111146, A113326, A113328 (y=3), A113329 (y=4), A113330 (y=5), A113331 (y=6).

Sequence in context: A372088 A166229 A109318 * A227791 A245102 A129148

Adjacent sequences: A113324 A113325 A113326 * A113328 A113329 A113330

KEYWORD

nonn

AUTHOR

Philippe Deléham and Paul D. Hanna, Oct 26 2005

STATUS

approved