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 A086406 #2 Mar 30 2012 18:58:53 %S A086406 1,2,11,84,857,10984,169803,3076688,63968273,1501465248,39277112843, %T A086406 1133193163840,35748951528681,1224258310112384,45233097633685643, %U A086406 1793524939926112512,75966131556225961121,3423203234058532082176 %N A086406 Main diagonal of number array A086404. %F A086406 a(n)=(n-sqrt(3))^n(1/2-sqrt(3)/6)+(n+sqrt(3))^n(1/2+sqrt(3)/6) %Y A086406 Cf. A086352. %K A086406 easy,nonn %O A086406 0,2 %A A086406 _Paul Barry_, Jul 19 2003