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 A349105 #22 Mar 28 2022 07:42:48 %S A349105 1,1,2,8,40,243,1796,15502,152608,1690613,20814208,281859540, %T A349105 4163795648,66636761575,1148477490304,21207704998010,417728195909632, %U A349105 8742243282090153,193720478508563456,4531158728871170080,111562803180301643776,2884156736234559267611 %N A349105 Expansion of e.g.f. 1/(1 - (sinh(x) + x*cosh(x))/2 ). %H A349105 Seiichi Manyama, <a href="/A349105/b349105.txt">Table of n, a(n) for n = 0..435</a> %F A349105 a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/2)} (k+1) * binomial(n,2*k+1) * a(n-2*k-1). %t A349105 With[{m = 21}, Range[0, m]! * CoefficientList[Series[1/(1 - (Sinh[x] + x*Cosh[x])/2), {x, 0, m}], x]] (* _Amiram Eldar_, Mar 26 2022 *) %o A349105 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(1/(1-(sinh(x)+x*cosh(x))/2))) %o A349105 (PARI) a(n) = if(n==0, 1, sum(k=0, (n-1)\2, (k+1)*binomial(n, 2*k+1)*a(n-2*k-1))); %Y A349105 Cf. A006154, A205571, A349104, A351937. %K A349105 nonn %O A349105 0,3 %A A349105 _Seiichi Manyama_, Mar 26 2022