OFFSET
0,4
COMMENTS
A001897 give the denominators of |Bernoulli(n)*Gould(n)| for even n, also the denominators of the cosecant numbers.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..314
MAPLE
b := n -> bernoulli(n)*2^add(i, i=convert(n, base, 2));
a := n -> numer(abs(b(2*n)));
MATHEMATICA
G[n_] := Sum[Mod[Binomial[n, k], 2], {k, 0, n}]; (* A001316 *) Table[Abs[BernoulliB[n]*G[n]], {n, 0, 20}][[1 ;; -1 ;; 2]]//Numerator (* G. C. Greubel, Sep 25 2018 *)
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Peter Luschny, May 02 2009
STATUS
approved