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 A352982 #22 Nov 02 2022 10:29:56
%S A352982 1,0,0,1,1,1,65,129,257,20196,60074,179196,17312754,68711380,
%T A352982 273234810,31605701625,156925970179,780248593545,105443761093411,
%U A352982 628709267031321,3752628871164355,580964060390826448,4043844561787569140,28170468954985342384
%N A352982 a(n) = Sum_{k=0..floor(n/3)} k^n.
%H A352982 Seiichi Manyama, <a href="/A352982/b352982.txt">Table of n, a(n) for n = 0..458</a>
%F A352982 G.f.: Sum_{k>=0} (k * x)^(3 * k) / (1 - k * x).
%t A352982 a[0] = 1; a[n_] := Sum[k^n, {k, 0, Floor[n/3]}]; Array[a, 24, 0] (* _Amiram Eldar_, Apr 13 2022 *)
%o A352982 (PARI) a(n) = sum(k=0, n\3, k^n);
%o A352982 (PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=0, N, (k*x)^(3*k)/(1-k*x)))
%o A352982 (Magma) [(&+[k^n: k in [0..Floor(n/3)]]): n in [0..40]]; // _G. C. Greubel_, Nov 01 2022
%o A352982 (SageMath) [sum( k^n for k in range((n//3)+1)) for n in range(41)] # _G. C. Greubel_, Nov 01 2022
%Y A352982 Cf. A089072, A352945, A352981.
%K A352982 nonn,easy
%O A352982 0,7
%A A352982 _Seiichi Manyama_, Apr 13 2022