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 A296793 #15 Feb 17 2021 07:32:52
%S A296793 1,2,9,67,705,9601,160429,3175579,72638209,1884974185,54709142101,
%T A296793 1755923320559,61748847320545,2360991253910069,97518218630249005,
%U A296793 4327060674324941491,205272207854416078849,10367500700785078039473,555414837143457708584101,31458118283019682610004279
%N A296793 a(n) = n! * [x^n] exp(x)*(sec(x) + tan(x))^n.
%H A296793 Vaclav Kotesovec, <a href="/A296793/b296793.txt">Table of n, a(n) for n = 0..300</a>
%H A296793 J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon transform, J. Combin. Theory, 17A 44-54 1996 (<a href="http://neilsloane.com/doc/bous.txt">Abstract</a>, <a href="http://neilsloane.com/doc/bous.pdf">pdf</a>, <a href="http://neilsloane.com/doc/bous.ps">ps</a>)
%H A296793 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>.
%H A296793 <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a>
%F A296793 a(n) ~ c * d^n * n^n, where d = 1.12712316036287986633533456353714856005183790513784733... and c = 1.61865092826915643845148401952113086265743345... - _Vaclav Kotesovec_, Dec 21 2017
%t A296793 Table[n! SeriesCoefficient[Exp[x] (Sec[x] + Tan[x])^n, {x, 0, n}], {n, 0, 19}]
%o A296793 (PARI) a(n) = Vec(serlaplace(exp(x)*(1/cos(x) + tan(x))^n))[n+1] \\ _Iain Fox_, Dec 20 2017
%Y A296793 Cf. A000111, A000667, A292756, A292759, A292976.
%Y A296793 Main diagonal of A322268.
%K A296793 nonn
%O A296793 0,2
%A A296793 _Ilya Gutkovskiy_, Dec 20 2017