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 A085390 #5 Oct 22 2019 18:08:29 %S A085390 1,3,20,180,2058,28672,472392,9000000,194871710,4729798656, %T A085390 127253992476,3760310514688,121096582031250,4222124650659840, %U A085390 158473248526494992,6371827248895377408,273260286537746369382,12451840000000000000000 %N A085390 a(n) = (n(n+1)^(n-2)+0^(n-2))/(n+1). %C A085390 A diagonal of square array A085388. %H A085390 Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Enumerative Formulas for Some Functions on Finite Sets</a> %Y A085390 Cf. A085389, A053506. %K A085390 easy,nonn %O A085390 2,2 %A A085390 _Paul Barry_, Jun 30 2003