OFFSET
0,2
FORMULA
a(n) = 4*A193365(n)*a(n-1) with a(0) = 1. - Johannes W. Meijer, Dec 21 2012
MAPLE
a := proc(n): denom(binomial(1/2, iquo(n, 2)))*product((4*i+2), i=1..2*n) end: seq(a(n), n=0..11); # Johannes W. Meijer, Dec 21 2012
MATHEMATICA
a[n_] := 2^(2n)*Product[2i+1, {i, 1, 2n}]*GCD[n!, 2^n]; Table[a[n], {n, 0, 11}] (* Jean-François Alcover, Dec 21 2012 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Dec 13 2012
STATUS
approved