This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A273352 #40 Aug 27 2018 01:51:20
%S A273352 1,34,11056,14873104,56814228736,495812444583424,8575634961418940416,
%T A273352 265929039218907754399744,13722623393637762299131396096,
%U A273352 1112372064432735526930220874072064,135292015985218004848567636630910795776,23782283324940089109797537284278352042000384
%N A273352 a(n) = 2^(2n+2) F(n) where F(n) is Ramanujan's F(n) = Sum_{k>=1} k^(4n-1)/(e^(Pi*k)-1) - 16^n* Sum_{k>=1} k^(4n-1)/(e^(4*Pi*k)-1).
%C A273352 Bisection of the reduced tangent numbers, A002105. This follows from the formulas. - _Franklin T. Adams-Watters_, May 22 2016
%H A273352 Math.Stackexchange.Com, Marko R. Riedel et al., <a href="http://math.stackexchange.com/questions/1792052/">Closed form of a sum by Ramanujan</a>
%F A273352 a(n) = 2^{2*n+2} * Bernoulli(4*n) * (1-2^(4*n))/(8*n).
%p A273352 S := proc(n, k) option remember;
%p A273352 if k=0 then `if`(n=0, 1, 0) else S(n, k-1) + S(n-1, n-k) fi end:
%p A273352 A273352 := n -> S(4*n-1, 4*n-1)/2^(2*n-1):
%p A273352 seq(A273352(n), n=1..12); # _Peter Luschny_, Jan 18 2017
%t A273352 Table[2^(2*n + 2)*BernoulliB[4*n]*(1 - 2^(4*n))/(8*n), {n, 1, 10}] (* _G. C. Greubel_, May 21 2016 *)
%t A273352 (* Function LMLlist defined in A293951 *)
%t A273352 LMLlist[4, 13] (* _Peter Luschny_, Aug 26 2018 *)
%Y A273352 Cf. A002105.
%Y A273352 Cf. A000182 (m=2), A293951 (m=3), this seq (m=4), A318258 (m=5).
%K A273352 nonn
%O A273352 1,2
%A A273352 _Marko Riedel_, May 20 2016