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 A013559 #23 Nov 14 2016 14:01:53
%S A013559 1,-1,1,1,-7,1,97,-55,-2063,143,17803,-968167,-250781,7000033,
%T A013559 -166831871,-571772647,43685848289,843598411471,-447550424579,
%U A013559 -1263845119891,84677077231169,740683182137153,-11657476758734011,-474904166544135457,28924058075775365981,-2379183287545454197
%N A013559 Numerator of [x^n] in the Taylor expansion of exp(cosech(x)-coth(x)).
%C A013559 The inner function is cosech(x)-coth(x) = -x/2 +x^3/24 -x^5/240 +17*x^7/40320 -31*x^9/725760 +691*x^11/159667200 -... with e.g.f numerators cosech(x)-coth(x) = sum b(n)x^n/(n+1)! apparently in A001469.
%H A013559 G. C. Greubel, <a href="/A013559/b013559.txt">Table of n, a(n) for n = 0..400</a>
%e A013559 1-x/2 +x^2/8 +x^3/48 -7*x^4/384 +x^5/1280 +97*x^6/46080 -...
%p A013559 S:= series(exp(csch(x)-coth(x)),x,51):
%p A013559 seq(numer(coeff(S,x,j)),j=0..50); # _Robert Israel_, Nov 14 2016
%t A013559 Numerator[Take[CoefficientList[Series[Exp[Csch[x] - Coth[x]], {x,0,40}], x], {1, -1, 1}]] (* _G. C. Greubel_, Nov 13 2016 *)
%Y A013559 Cf. A013521, A096664 (bisections?)
%K A013559 sign
%O A013559 0,5
%A A013559 Patrick Demichel (patrick.demichel(AT)hp.com)
%E A013559 Name edited by _R. J. Mathar_, Dec 22 2011