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 A352429 #10 Mar 23 2022 09:51:13 %S A352429 1,1,2,6,24,121,732,5166,41664,378001,3810512,42253926,511139904, %T A352429 6698457481,94535404992,1429477706286,23056267551744,395120495014561, %U A352429 7169579673404672,137321623511274246,2768602189953629184,58609968225266985241,1299827736206335767552,30137364376923272989806 %N A352429 a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/4)} binomial(n,4*k+1) * a(n-4*k-1). %H A352429 Seiichi Manyama, <a href="/A352429/b352429.txt">Table of n, a(n) for n = 0..449</a> %F A352429 E.g.f.: 1 / (1 - Sum_{k>=0} x^(4*k+1) / (4*k+1)!). %F A352429 E.g.f.: 1 / (1 - (sin(x) + sinh(x)) / 2). %t A352429 a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, 4 k + 1] a[n - 4 k - 1], {k, 0, Floor[(n - 1)/4]}]; Table[a[n], {n, 0, 23}] %t A352429 nmax = 23; CoefficientList[Series[1/(1 - Sum[x^(4 k + 1)/(4 k + 1)!, {k, 0, nmax}]), {x, 0, nmax}], x] Range[0, nmax]! %o A352429 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=0, N\4, x^(4*k+1)/(4*k+1)!)))) \\ _Seiichi Manyama_, Mar 23 2022 %Y A352429 Cf. A000670, A006154, A243665, A291975, A306347, A352428, A352430. %K A352429 nonn %O A352429 0,3 %A A352429 _Ilya Gutkovskiy_, Mar 16 2022