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 A355044 #13 Jun 21 2022 17:02:26 %S A355044 10,37,130,453,1584,5577,19786,70720,254524,921842,3357908,12294995, %T A355044 45229500,167093505,619689690,2306312580,8611143420,32246815350, %U A355044 121085968380,455817192090,1719872196432,6503354706762,24640476660420,93534587913648,355675196682904 %N A355044 Number of coalescent histories for matching gene trees and species trees with n leaves and a 5-leaf seed tree. %C A355044 a(n) is the number of coalescent histories for matching gene tree G and species tree S, where G and S are identically labeled and have shape (...((((A_1,A_2),A_3),(A_4,A_5)),.),.),...), with n leaves. %H A355044 N. A. Rosenberg, <a href="https://doi.org/10.1109/tcbb.2013.123">Coalescent histories for caterpillar-like families</a>, IEEE/ACM Trans. Comp. Biol. Bioinformat. 10 (2013), 1253-1262. %F A355044 a(n) = ((23*n^2-131*n+180)/(4*(2n-3)*(2n-5)))*(2n-2)!/((n-1)!*n!). %F A355044 a(n) = ((23*n^2-131*n+180)/(4*(2n-3)*(2n-5)))*A000108(n-1). %Y A355044 Cf. A000108, A070031 (for the same computation with a 4-leaf seed tree). %K A355044 nonn %O A355044 5,1 %A A355044 _Noah A Rosenberg_, Jun 16 2022