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 A157255 #10 Mar 01 2024 06:09:50
%S A157255 1,17,7625597484988
%N A157255 a(n) = sigma_(n^n)(n).
%H A157255 Amiram Eldar, <a href="/A157255/b157255.txt">Table of n, a(n) for n = 1..4</a>
%t A157255 Table[DivisorSigma[n^n,n],{n,1,5}]
%o A157255 (PARI) a(n) = sigma(n, n^n); \\ _Amiram Eldar_, Mar 01 2024
%Y A157255 Cf. A000312, A023887.
%K A157255 bref,nonn
%O A157255 1,2
%A A157255 _Vladimir Joseph Stephan Orlovsky_, Feb 26 2009