A043304 Denominator of B(4n+2)/(8n+4) where B(m) are the Bernoulli numbers.

504, 264, 24, 28728, 552, 24, 171864, 24, 24, 151704, 1128, 264, 86184, 1416, 24, 776664, 18744, 24, 39816, 1992, 24, 9796248, 24, 24, 51912, 2568, 66792, 504, 24, 24, 1098185256, 34584, 24, 3292632, 24, 24, 25951464, 552, 24, 42143976, 4008

Offset

1,1

References

Bruce Berndt, Ramanujan's Notebooks Part II, Springer-Verlag; see Infinite series, p. 262.

Links

Seiichi Manyama, Table of n, a(n) for n = 1..500

Formula

B(4n+2)/(8n+4) = Sum_{k>=1} k^(4n+1)/(exp(2Pi*k)-1).

Mathematica

Denominator[Table[BernoulliB[4n+2]/(8n+4), {n, 50}]] (* Harvey P. Dale, Sep 30 2012 *)

Prog

(PARI) a(n) = denominator(bernfrac(4*n+2)/(8*n+4)); \\ Michel Marcus, Feb 16 2021

Crossrefs

Cf. A043303.

Sequence in context: A133525 A361252 A066525 * A045212 A262873 A228164

Adjacent sequences: A043301 A043302 A043303 * A043305 A043306 A043307

Keyword

easy,frac,nonn

Author

Benoit Cloitre, Apr 04 2002

Status

approved