OFFSET
0,4
COMMENTS
Normally sequences like this are not included, since with the alternating 0's deleted it is already in the database.
From Michael Somos, Mar 04 2004: (Start)
Stirling transform of a(n) = [1,0,6,0,120,0,5040,...] is A089677(n) = [1,1,7,37,271,...].
Stirling transform of a(n-1) = [0,1,0,6,0,120,0,...] is A000670(n-1) = [0,1,3,13,75,...].
Stirling transform of a(n-1) = [1,1,0,6,0,120,0,...] is A052856(n-1) = [1,2,4,14,76,...]. (End)
REFERENCES
D. R. Hofstadter, Fluid Concepts and Creative Analogies: Computer Models of the Fundamental Mechanisms of Thought, (together with the Fluid Analogies Research Group), NY: Basic Books, 1995.
LINKS
FORMULA
E.g.f.: -log(cos(arcsin(x))). - Vladimir Kruchinin, Jun 15 2011
MAPLE
BB:=[T, {T=Prod(Z, F), F=Sequence(B), B=Prod(Z, Z)}, labeled]: seq(count(BB, size=i), i=0..24); # Zerinvary Lajos, Apr 22 2007
MATHEMATICA
nn = 20; Rest[ Range[0, nn]! CoefficientList[ Series[ Log[(1 - x^2)^(-1/2)], {x, 0, nn}], x]] (* Geoffrey Critzer, May 29 2013 *)
Riffle[Range[1, 25, 2]!, 0, {1, -1, 2}] (* Harvey P. Dale, Mar 10 2017 *)
PROG
(PARI) a(n)=if(n<0, 0, if(n%2, n!, 0));
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved