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 A381206 #10 Feb 17 2025 08:18:12
%S A381206 1,2,6,30,192,1450,12960,133574,1550976,20055186,285903360,4452231982,
%T A381206 75186726912,1368588922298,26709799753728,556339845854550,
%U A381206 12318065768693760,288894650033594914,7154212267816648704,186545064693433665854,5108590743587243950080
%N A381206 Expansion of e.g.f. 1/(1 - x*cosh(x))^2.
%C A381206 As stated in the comment of A185951, A185951(n,0) = 0^n.
%F A381206 a(n) = Sum_{k=0..n} (k+1)! * A185951(n,k).
%o A381206 (PARI) a185951(n, k) = binomial(n, k)/2^k*sum(j=0, k, (2*j-k)^(n-k)*binomial(k, j));
%o A381206 a(n) = sum(k=0, n, (k+1)!*a185951(n, k));
%Y A381206 Cf. A205571, A381207.
%Y A381206 Cf. A185951.
%K A381206 nonn
%O A381206 0,2
%A A381206 _Seiichi Manyama_, Feb 17 2025