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%I #14 Apr 24 2018 23:01:15
%S 1,1,1,1,1,1,1,1,1,1,1,17,1,1,1,1,1,1,1,527,1,1,1,1,31,1,1,731,1,41,1,
%T 1,1,37,1333,17,1,1,1,31,1,1,1,17,73,1,1,1,43,1271,59,629,1,73,2759,
%U 43,1,1,1,17,1,67,7519,1,31,89,1,289,1,29020032511,1,10573,1,1,1,2227,486029
%N Numerator of 2*BernoulliB[2*(n+1)]*(4^(n+1)-1)/(2*(n+1))] divided by numerator of the series coefficients of 1/(1 + Cosh[x]).
%C Ratios of two similar sequences.
%C This sequence is related to the sequences of the numerators and denominators of the Taylor series for tan(x), i.e., A002430 and A036279, and the similar sequences A160469 and A156769. - _Johannes W. Meijer_, May 24 2009
%H Michael De Vlieger, <a href="/A089170/b089170.txt">Table of n, a(n) for n = 0..5000</a>
%F For n>=0, a(n)=c(n+1) where c(n)=numerator((4^n-1)*B(2*n)/n)/numerator((4^n-1)*B(2*n)/(2*n)!), B(k) denotes the k-th Bernoulli number. - C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 19 2004
%p seq(numer(2*bernoulli(2*n)*(4^n-1)/(2*n))/numer((4^n-1)*bernoulli(2*n)/(2*n)!),n=1..100); # C. Ronaldo
%t Table[Numerator[2*BernoulliB[2*n]*(4^n -1)/(2*n)]/Numerator[SeriesCoefficient[Series[1/(1+Cosh[x]), {x, 0, 2n}], 2n-2]], {n, 1, 128}]
%Y Cf. A002425.
%Y From _Johannes W. Meijer_, May 24 2009: (Start)
%Y Equals A160469(n+1)/A002430(n+1).
%Y Equals A156769(n+1)/A036279(n+1).
%Y (End)
%K nonn
%O 0,12
%A _Wouter Meeussen_, Dec 07 2003
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