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 A292756 #14 Jan 05 2025 19:51:41
%S A292756 1,3,9,29,105,433,2029,10709,63025,409713,2917749,22599389,189200745,
%T A292756 1702839193,16397919469,168248900069,1832540103265,21118133619873,
%U A292756 256725609081189,3283461599832749,44074814323890585,619564244562907753,9102144892897546909,139495284063955397429
%N A292756 Expansion of e.g.f. exp(x)*(tan(x)+sec(x))^2.
%H A292756 C. K. Cook, M. R. Bacon, and R. A. Hillman, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Papers1/55-3/CookBaconHillman01222017.pdf">Higher-order Boustrophedon transforms for certain well-known sequences</a>, Fib. Q., 55(3) (2017), 201-208.
%F A292756 a(n) ~ 2^(n + 9/2) * n^(n + 3/2) / (Pi^(n + 3/2) * exp(n - Pi/2)). - _Vaclav Kotesovec_, Jun 02 2019
%t A292756 nmax = 20; CoefficientList[Series[Exp[x]*(Tan[x]+Sec[x])^2, {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Jun 02 2019 *)
%Y A292756 Cf. A000667.
%K A292756 nonn
%O A292756 0,2
%A A292756 _N. J. A. Sloane_, Sep 26 2017