OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..400
Peter Luschny, Multifactorials
FORMULA
MAPLE
MATHEMATICA
a[n_] := With[{m = Mod[n, 2]}, Product[If[Mod[k, 2] == m, k, 1], {k, 1, 2*n}]]; Table[a[n], {n, 0, 18}] (* Jean-François Alcover, Jan 27 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Jun 23 2011
STATUS
approved