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 A378065 #7 Nov 18 2024 13:01:09
%S A378065 1,1,-24,-74,2976,15376,-906624,-6563024,514546176,4789470976,
%T A378065 -469222938624,-5338232282624,627559296638976,8437702651826176,
%U A378065 -1157248322241921024,-17953287144063002624,2814090582404042981376,49478116534660975230976,-8724885890905288434253824
%N A378065 a(n) = (-10)^n * Euler(n, 2/5). Row 5 of A378066.
%F A378065 a(n) = n! * [x^n] exp(x)/cosh(5*x).
%F A378065 a(n) = Sum_{j=0..n} (-5)^j*binomial(n, j)*Euler(j).
%p A378065 a := n -> (-10)^n * euler(n, 2/5): seq(a(n), n = 0..18);
%p A378065 # Or:
%p A378065 ser := series(exp(x)/cosh(5*x), x, 20):
%p A378065 seq(n!*coeff(ser, x, n), n = 0..18);
%Y A378065 Cf. A378066.
%K A378065 sign
%O A378065 0,3
%A A378065 _Peter Luschny_, Nov 17 2024