OFFSET
0,4
FORMULA
a(n) = numerator(-2*n*Zeta(1 - 2*n)*(1/2 - n)! / sqrt(Pi)) for n >= 1.
EXAMPLE
r(n) = 1/2, 1/6, 1/15, 2/63, 4/225, 8/693, 11056/1289925, 32/4455, ...
MAPLE
a := n -> bernoulli(2*n)*(1/2 - n)! / sqrt(Pi):
seq(numer(simplify(a(n))), n = 0..21);
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Peter Luschny, Jun 20 2020
STATUS
approved