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 A057868 Denominator of "modified Bernoulli number" b(2n) = Bernoulli(2*n)/(2*n*n!). 1

%I

%S 48,5760,362880,19353600,958003200,31384184832000,2092278988800,

%T 341459930972160000,183927391818153984000,32114306507931648000000,

%U 620448401733239439360000,81303558563123696133734400000

%N Denominator of "modified Bernoulli number" b(2n) = Bernoulli(2*n)/(2*n*n!).

%H D. Bar-Natan, T. T. Q. Le and D. P. Thurston, <a href="http://arXiv.org/abs/math.QA/0204311">Two applications of elementary knot theory ...</a> Geometry and Topology 7-1 (2003) 1-31.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ModifiedBernoulliNumber.html">Modified Bernoulli Numbers.</a>

%H <a href="/index/Be#Bernoulli">Index entries for sequences related to Bernoulli numbers.</a>

%e The sequence of modified Bernoulli numbers begins 1/48, -1/5760, 1/362880, -1/19353600, 1/958003200, -691/31384184832000, ...

%t a[n_] := Denominator[ BernoulliB[2n] / (8n^2*(2n-1)!)];

%t Table[a[n], {n, 1, 12}] (* _Jean-François Alcover_, Jun 07 2012 *)

%Y Numerators are in A001067.

%K nonn,frac

%O 1,1

%A _Eric W. Weisstein_

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Last modified October 1 04:06 EDT 2020. Contains 337441 sequences. (Running on oeis4.)