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 A003705 M3172 #21 Apr 11 2014 04:45:17
%S A003705 1,1,-3,-107,-1095,41897,3027637,34528445,-11832720271,-1190157296815,
%T A003705 22592230600813,23107531656941541,2633888933338158633,
%U A003705 -362759000929143575815,-189312598480126813670107,-18315162183020706728157939
%N A003705 E.g.f. tan(sin(x)) (odd powers only).
%D A003705 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A003705 Vincenzo Librandi, <a href="/A003705/b003705.txt">Table of n, a(n) for n = 0..100</a>
%F A003705 a(n) = 2*sum(m=0..n-1, ((sum(j=1..2*m+1, j!*2^(-j)*(-1)^(j+1)*stirling2(2*m+1,j)))*sum(i=0..(2*m+1)/2, (2*i-(2*m+1))^(2*n-1)*binomial(2*m+1,i)*(-1)^(n-i)))/(2*m+1)!). [_Vladimir Kruchinin_, Jun 11 2011]
%t A003705 With[{nn = 50}, Take[CoefficientList[Series[Tan[Sin[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* _Vincenzo Librandi_, Apr 11 2014 *)
%o A003705 (Maxima)
%o A003705 a(n):=2*sum(((sum(j!*2^(-j)*(-1)^(j+1)*stirling2(2*m+1,j),j,1,2*m+1))*sum((2*i-(2*m+1))^(2*n-1)*binomial(2*m+1,i)*(-1)^(n-i),i,0,(2*m+1)/2))/(2*m+1)!,m,0,n-1); /* _Vladimir Kruchinin_, Jun 11 2011 */
%K A003705 sign
%O A003705 0,3
%A A003705 _R. H. Hardin_, _Simon Plouffe_
%E A003705 Changed offset from 1 to 0 by _Vincenzo Librandi_, Apr 11 2014