OFFSET
1,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..260
Ira Gessel, On Miki's identity for Bernoulli numbers J. Number Theory 110 (2005), no. 1, 75-82.
FORMULA
Miki's identity : B(n)*H(n)*(2/n) = sum(i=2, n-2, B(i)/i*B(n-i)/(n-i)*(1-C(n, i)))
MATHEMATICA
Table[ BernoulliB[2n] * HarmonicNumber[2n] / n // Numerator // Abs, {n, 1, 16}] (* Jean-François Alcover, Mar 24 2015 *)
PROG
(PARI) a(n)=numerator((-1)^(n+1)*bernfrac(2*n)*sum(k=1, 2*n, 1/k)/n)
(Python)
from sympy import bernoulli, harmonic, numer
def a(n):
return numer(bernoulli(2 * n) * harmonic(2 * n) * (-1)**(n + 1) / n)
[a(n) for n in range(1, 31)] # Indranil Ghosh, Aug 04 2017
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Benoit Cloitre, Jun 15 2003
STATUS
approved