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 A352946 #13 Apr 14 2022 02:52:06
%S A352946 1,1,1,1,2,3,4,6,10,16,25,42,73,125,217,391,714,1305,2428,4612,8830,
%T A352946 17038,33377,66216,132349,267075,545329,1123693,2333278,4889751,
%U A352946 10342468,22043954,47340802,102504532,223654713,491393646,1087353601,2423448817,5437568233
%N A352946 a(n) = Sum_{k=0..floor(n/3)} (n-3*k)^k.
%F A352946 G.f.: Sum_{k>=0} x^k / (1 - k * x^3).
%F A352946 a(n) ~ sqrt(2*Pi/3) * (n/LambertW(exp(1)*n))^(n*(1 - 1/LambertW(exp(1)*n))/3 + 1/2) / sqrt(1 + LambertW(exp(1)*n)). - _Vaclav Kotesovec_, Apr 14 2022
%o A352946 (PARI) a(n) = sum(k=0, n\3, (n-3*k)^k);
%o A352946 (PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-k*x^3)))
%Y A352946 Cf. A026898, A352944.
%Y A352946 Cf. A001840.
%K A352946 nonn,easy
%O A352946 0,5
%A A352946 _Seiichi Manyama_, Apr 09 2022