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 A337989 #5 Oct 09 2020 05:18:01
%S A337989 1,2,120,131204813713122
%N A337989 Number of compositions (ordered partitions) of n^n into n-th powers.
%C A337989 The next term is too large to include.
%H A337989 <a href="/index/Com#comp">Index entries for sequences related to compositions</a>
%F A337989 a(n) = [x^(n^n)] 1 / (1 - Sum_{k>=1} x^(k^n)).
%e A337989 a(3) = 120 because 3^3 = 27 and we have [27], [8, 8, 8, 1, 1, 1] (20 permutations), [8, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] (78 permutations), [8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] (20 permutations), [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] and 1 + 20 + 78 + 20 + 1 = 120.
%t A337989 Table[SeriesCoefficient[1/(1 - Sum[x^(k^n), {k, 1, n}]), {x, 0, n^n}], {n, 1, 4}]
%Y A337989 Cf. A011782, A224366, A290247, A331402.
%K A337989 nonn
%O A337989 1,2
%A A337989 _Ilya Gutkovskiy_, Oct 06 2020