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 A185634 #20 Jun 11 2025 19:45:24 %S A185634 1,2,21,204,2605,39990,720601,14913080,348678441,9090909090, %T A185634 261535698061,8230246567620,281241170407093,10371206370520814, %U A185634 410525522232055665,17361641481138401520,781282469559318055057,37275544492386193492506,1879498672877297909667781 %N A185634 Number of n-length cycles from any point in a complete graph on n nodes. %C A185634 If M is the n X n matrix filled with ones, a(n) is the upper left element of (M-Id)^n. %F A185634 a(n) = floor((n-1)^n/n) + ((-1)^n+1)/2. %F A185634 a(n) = floor((n-1)^n/n)+1 for n odd, a(n) = floor((n-1)^n/n) for n even. %e A185634 In a complete graph in 5 nodes, there are 204 different cycles with a length of 5, from a point to itself. %Y A185634 Cf. A173499. %K A185634 easy,nonn %O A185634 2,2 %A A185634 _Sébastien Dumortier_, Dec 18 2012