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 A332239 #4 Feb 07 2020 20:50:28
%S A332239 1,0,2,11,96,1058,14292,229273,4268583,90599501,2161197285,
%T A332239 57273924968,1670125069883,53158796477452,1834276943996477,
%U A332239 68212851126889959,2719975462998554200,115777392670653923870,5240030485305934701421,251291379101960875175412
%N A332239 a(n) = n^(n-2) - Sum_{k=1..n-1} k^(k-2) * a(n-k).
%F A332239 G.f.: 1 - 1 / (1 + Sum_{k>=1} k^(k-2) * x^k).
%t A332239 a[n_] := a[n] = n^(n - 2) - Sum[k^(k - 2) a[n - k], {k, 1, n - 1}]; Table[a[n], {n, 1, 20}]
%t A332239 nmax = 20; CoefficientList[Series[1 - 1/(1 + Sum[k^(k - 2) x^k, {k, 1, nmax}]), {x, 0, nmax}], x] // Rest
%Y A332239 Cf. A000272, A003319, A277611, A296715, A332238.
%K A332239 nonn
%O A332239 1,3
%A A332239 _Ilya Gutkovskiy_, Feb 07 2020