A335954 a(n) = Numerator(-2*n*HurwitzZeta(1 - 2*n, -1/2)) for n > 0, and a(0) = 1.

1, 11, 127, 221, 367, -1895, 1447237, -57253, 118526399, -5749677193, 91546283957, -1792042789427, 1982765468376757, -286994504449237, 3187598676787485443, -4625594554880206360895, 16555640865486520494719, -22142170099387402072693, 904185845619475242495903560731

Offset

0,2

Links

Table of n, a(n) for n=0..18.

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

Cf. A033469 (denominators), A001896 (evaluated at x=+1/2).

Sequence in context: A296732 A156970 A174270 * A333244 A141987 A048394

Adjacent sequences: A335951 A335952 A335953 * A335955 A335956 A335957

Keyword

sign

Author

Peter Luschny, Jul 21 2020

Status

approved