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Denominator of B(4n+2)/(8n+4) where B(m) are the Bernoulli numbers.
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%I #20 Feb 16 2021 13:51:21

%S 504,264,24,28728,552,24,171864,24,24,151704,1128,264,86184,1416,24,

%T 776664,18744,24,39816,1992,24,9796248,24,24,51912,2568,66792,504,24,

%U 24,1098185256,34584,24,3292632,24,24,25951464,552,24,42143976,4008

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

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

%H Seiichi Manyama, <a href="/A043304/b043304.txt">Table of n, a(n) for n = 1..500</a>

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

%t Denominator[Table[BernoulliB[4n+2]/(8n+4),{n,50}]] (* _Harvey P. Dale_, Sep 30 2012 *)

%o (PARI) a(n) = denominator(bernfrac(4*n+2)/(8*n+4)); \\ _Michel Marcus_, Feb 16 2021

%Y Cf. A043303.

%K easy,frac,nonn

%O 1,1

%A _Benoit Cloitre_, Apr 04 2002