A276667 a(n) = numerator(b(2*n)) with b(n) = n!*Bernoulli(n,1/2)/(n*(n-1)) for n>=2, b(0)=1, b(1)=0.

1, -1, 7, -31, 381, -268275, 190954395, -8940271725, 336335206772565, -174821527924918875, 54202314805255255275, -5543854406384412644150625, 3114120189113602279924264875, -14151357141482747539875264868125, 10216485085859695459247479126412709375

Offset

0,3

Links

Table of n, a(n) for n=0..14.

Maple

b := n -> `if`(n<2, 1-n, (n-2)!*bernoulli(n, 1/2)):
a := n -> numer(b(2*n)):
seq(a(n), n=0..14);

Crossrefs

Cf. A276668 (denominators).

Sequence in context: A253596 A298958 A153028 * A322894 A232993 A135630

Adjacent sequences: A276664 A276665 A276666 * A276668 A276669 A276670

Keyword

sign,frac

Author

Peter Luschny, Sep 24 2016

Status

approved