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 A062810 #19 Mar 24 2019 08:36:01
%S A062810 1,3,7,17,45,131,419,1465,5561,22755,99727,465537,2303829,12037571,
%T A062810 66174411,381560425,2301307841,14483421859,94909491607,646309392369,
%U A062810 4565559980989,33401808977411,252713264780595,1974606909857945
%N A062810 a(n) = Sum_{i=1..n} i^(n - i) + (n - i)^i.
%H A062810 Seiichi Manyama, <a href="/A062810/b062810.txt">Table of n, a(n) for n = 1..600</a>
%F A062810 a(n) = 2 * A026898(n-1) - 1.
%F A062810 a(n) = 2 * A003101(n-1) + 1.
%t A062810 Sum[i^(n - i) + (n - i)^i, {i, 1, n}]
%o A062810 (PARI) a(n) = sum(i=1, n, i^(n-i) + (n-i)^i); \\ _Michel Marcus_, Mar 24 2019
%Y A062810 Cf. A003101, A026898, A062811, A062812.
%K A062810 nonn,easy
%O A062810 1,2
%A A062810 _Olivier Gérard_, Jun 23 2001