0,3

Stirling transform of A005359(n)=[0,2,0,24,0,720,...] is a(n)=[0,2,6,38,270,...]. - Michael Somos Mar 04 2004

Stirling transform of -(-1)^n*A052657(n-1)=[0,0,2,-6,48,-240,...] is a(n-1)=[0,0,2,6,38,270,...]. - Michael Somos Mar 04 2004

Stirling transform of -(-1)^n*A052558(n-1)=[1,-1,4,-12,72,-360,...] is a(n-1)=[1,0,2,6,38,270,...]. - Michael Somos Mar 04 2004

Stirling transform of 2*A052591(n)=[2,4,24,96,...] is a(n+1)=[2,6,38,270,...]. - Michael Somos Mar 04 2004

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 808

C. G. Bower, Transforms (2)

a( n) = (A000670(n) + (-1)^n)/2 = Sum_{k>=0} (k-1)^n/2^(k+1). - Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 02 2003

Also, a(n) = Sum[k=0..[n/2], (2k)!*Stirling2(n, 2k)]. - R. Stephan, May 23 2004

E.g.f.: 1/(exp(x)*(2-exp(x))).

spec := [S, {B=Prod(C, C), C=Set(Z, 1 <= card), S=Sequence(B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);

(PARI) a(n)=if(n<0, 0, n!*polcoeff(subst(1/(1-y^2), y, exp(x+x*O(x^n))-1), n))

Inverse binomial transform of A000670.

Sequence in context: A027322 A085447 A078673 this_sequence A068184 A067106 A032111

Adjacent sequences: A052838 A052839 A052840 this_sequence A052842 A052843 A052844

easy,nonn

encyclopedia(AT)pommard.inria.fr, Jan 25 2000