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 A349267 #12 Oct 30 2024 12:15:24
%S A349267 2,8,96,1408,29184,739328,22634496,806453248,32864600064,
%T A349267 1506300919808,76717014122496,4297849713983488,262665886073094144,
%U A349267 17390688314209599488,1239981021847665770496,94727563504456856240128,7719096548270543600615424,668321603392783694711226368
%N A349267 Generalized Euler numbers, a(n) = n!*[x^n](sec(8*x)*2*(sin(4*x) + cos(4*x))).
%C A349267 For references and cross references, compare the overview in A349264.
%H A349267 Matthew House, <a href="/A349267/b349267.txt">Table of n, a(n) for n = 0..353</a>
%p A349267 sec(8*x)*2*(sin(4*x) + cos(4*x)): series(%, x, 20): seq(n!*coeff(%, x, n), n = 0..17);
%t A349267 m = 17; CoefficientList[Series[2 * Sec[8*x] * (Sin[4*x] + Cos[4*x]), {x, 0, m}], x] * Range[0, m]! (* _Amiram Eldar_, Nov 21 2021 *)
%Y A349267 Row 8 of A349271.
%Y A349267 Bisections: A064069, A064073.
%Y A349267 Cf. A349264.
%K A349267 nonn
%O A349267 0,1
%A A349267 _Peter Luschny_, Nov 21 2021