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 A284467 #49 Jun 21 2018 20:12:26
%S A284467 1,1,-2,1,2,-2,0,-5,10,1,-15,10,-1,18,-39,4,50,-24,-14,-69,165,-70,
%T A284467 -83,-20,154,161,-550,313,55,410,-960,102,1074,-406,-506,-1344,3581,
%U A284467 -1791,-833,-1833,4995,205,-6993,2982,2461,7649,-19791,9495,4986,9581,-26745,0
%N A284467 Expansion of Product_{k>=1} (1 + x^(2*k-1))^(2*k-1)/(1 + x^(2*k))^(2*k).
%H A284467 Robert Israel, <a href="/A284467/b284467.txt">Table of n, a(n) for n = 0..2000</a>
%F A284467 G.f.: exp(Sum_{k>=1} (-1)^(k+1)*x^k/(k*(1 + x^k)^2)). - _Ilya Gutkovskiy_, Jun 20 2018
%p A284467 N:= 100: # to get a(0)..a(N)
%p A284467 P:= mul((1+x^(2*k-1))^(2*k-1)/(1+x^(2*k))^(2*k),k=1..N/2):
%p A284467 S:= series(P,x,N+1):
%p A284467 seq(coeff(S,x,j),j=0..N); # _Robert Israel_, Apr 16 2017
%t A284467 nmax = 60; CoefficientList[Series[Product[(1 + x^(2*k-1))^(2*k-1)/(1 + x^(2*k))^(2*k), {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Apr 15 2017 *)
%Y A284467 Cf. A224364, A262736, A278710, A281683, A284474.
%K A284467 sign
%O A284467 0,3
%A A284467 _Seiichi Manyama_, Apr 15 2017