0,3

Normally sequences like this are not included, since with the alternating 0's deleted it is already in the database.

Stirling transform of a(n)=[0,2,0,24,0,720,...] is A052841(n)=[0,2,6,38,270,...]. -Michael Somos Mar 04 2004

Stirling transform of a(n-1)=[1,0,2,0,24,0,...] is A000670(n-1)=[1,1,3,13,75,...]. - Michael Somos Mar 04 2004

Stirling transform of a(n-1)=[0,0,2,0,24,0,...] is A052875(n-1)=[0,0,2,12,74,...]. - Michael Somos Mar 04 2004

Stirling transform of (-1)^n*A052811(n)=[0,2,-6,46,-340,...] is a(n)=[0,2,0,24,0,...]. - Michael Somos Mar 04 2004

Douglas Hofstadter, "Fluid Concepts and Creative Analogies: Computer Models of the Fundamental Mechanisms of Thought".

Index entries for sequences related to factorial numbers

E.g.f. 1/(1-x^2) = d/dx log(sqrt((1+x)/(1-x))). a(2n)=(2n)!, a(2n+1)=0.

BB:={E=Prod(Z, Z), S=Union(Epsilon, Prod(S, E))}: ZL:=[S, BB, labeled]: > seq(count(ZL, size=n), n=0..25); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 22 2007

a:=n->n!+(-1)^n*n!: seq(a(n)/2, n=0..25); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 25 2008

(PARI) a(n)=if(n<0, 0, if(n%2, 0, n!))

Sequence in context: A138551 A133490 A051728 this_sequence A008842 A130915 A127067

Adjacent sequences: A005356 A005357 A005358 this_sequence A005360 A005361 A005362

nonn

njas, Russ Cox (rsc(AT)swtch.com)