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 A270666 #4 Mar 21 2016 07:18:31
%S A270666 1,1,2,14,48,416,3360,29504,274176,3503104,45192960,579956992,
%T A270666 8982251520,138130720768,2456648183808,45868468109312,871166211686400,
%U A270666 17536583860060160,393972064172900352,8704569607311982592,210657904645299240960,5322004254737369399296
%N A270666 E.g.f.: Product_{k>=1} (1 + tan(x^k)).
%t A270666 nmax = 25; Range[0, nmax]! * CoefficientList[Series[Product[(1+Tan[x^k]), {k, 1, nmax}], {x, 0, nmax}], x]
%Y A270666 Cf. A130263, A270294, A270598, A270662, A270664, A270665.
%K A270666 nonn
%O A270666 0,3
%A A270666 _Vaclav Kotesovec_, Mar 21 2016