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 A081164 #16 Jan 11 2024 03:03:45 %S A081164 1,1,1,2,2,4,4,11,15,25,32,64,88,155,234,423,647,1184,1800 %N A081164 Number of distinct cycle lengths in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506. %C A081164 This is the number of nonzero, non-constant terms of the polynomials M_n(x) Donaghey gives on the page 81 of his paper. The term x^18 seems to have been accidentally dropped from the polynomial M_7(x). %H A081164 Robert Donaghey, <a href="https://doi.org/10.1016/0095-8956(80)90045-3">Automorphisms on Catalan trees and bracketing</a>, J. Combin. Theory, Series B, 29 (1980), 75-90. %H A081164 Antti Karttunen, <a href="/A089408/a089408.c.txt">Counted with the help of this C program</a>. %Y A081164 Cf. A081166, A060114. %K A081164 nonn,more %O A081164 0,4 %A A081164 _Wouter Meeussen_ and _Antti Karttunen_, Mar 10 2003