OFFSET
0,2
FORMULA
a(n) = Numerator(Bernoulli(2*n, -1/2)).
MAPLE
a := n -> numer(`if`(n=0, 1, -2*n*Zeta(0, 1-2*n, -1/2))): seq(a(n), n=0..18);
MATHEMATICA
a[0] := 1; a[n_] := -2 n HurwitzZeta[1 - 2 n, -1/2]; Array[a, 18, 0] // Numerator
PROG
(PARI) a(n) = numerator(subst(bernpol(2*n, x), x, -1/2)); \\ Michel Marcus, Jul 21 2020
CROSSREFS
KEYWORD
sign
AUTHOR
Peter Luschny, Jul 21 2020
STATUS
approved