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 A081162 #8 Jan 11 2024 09:18:13 %S A081162 0,0,0,0,0,0,0,1,0,4,0,15,0,56,0,185,0,655,0 %N A081162 Number of even cycles in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506, with two fixed-points of A057163. %C A081162 Because A057163 can fix only binary trees of odd size, the even-indexed terms are all 0. %Y A081162 Bisection: A081163. Cf. A081150, A081157, A081160. %Y A081162 Cf. A014137, A014138, A057505, A057506, A057163. %K A081162 nonn,more %O A081162 0,10 %A A081162 _Wouter Meeussen_ and _Antti Karttunen_, Mar 10 2003