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 A081155 #8 Jan 11 2024 07:15:37 %S A081155 1,1,0,1,0,2,0,3,0,6,0,12,0,20,0,59,0,120,0 %N A081155 Number of odd cycles in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506, with fixed-points of both A057163 and A057164. %C A081155 See comment at A080973. Because A057163 can fix only binary trees of odd size, the even-indexed terms are all 0 after n>0. %F A081155 a(n) = A081148(n)-A081153(n). %Y A081155 Bisection: A081156. %Y A081155 Cf. A081148, A081153. %Y A081155 Cf. A014137, A014138, A057505, A057506, A057163, A057164. %K A081155 nonn,more %O A081155 0,6 %A A081155 _Wouter Meeussen_ and _Antti Karttunen_, Mar 10 2003