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 A318853 #5 Sep 04 2018 17:33:23 %S A318853 0,1,1,2,4,9,20,48,114,284,714,1829,4731,12391,32711,87083,233347, %T A318853 629132,1705026,4642964,12696279,34851400,95996673,265251812, %U A318853 735029389,2042187079,5687726124,15876511622,44409196932,124459720195,349434222059,982723600768 %N A318853 Number of rooted trees with n nodes such that no more than six isomorphic subtrees extend from the same node. %H A318853 Alois P. Heinz, <a href="/A318853/b318853.txt">Table of n, a(n) for n = 0..2136</a> %p A318853 h:= proc(n, m, t) option remember; `if`(m=0, binomial(n+t, t), %p A318853 `if`(n=0, 0, add(h(n-1, m-j, t+1), j=1..min(6, m)))) %p A318853 end: %p A318853 b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, %p A318853 add(b(n-i*j, i-1)*h(a(i), j, 0), j=0..n/i))) %p A318853 end: %p A318853 a:= n-> `if`(n<2, n, b(n-1$2)): %p A318853 seq(a(n), n=0..35); %Y A318853 Column k=6 of A318757. %K A318853 nonn %O A318853 0,4 %A A318853 _Alois P. Heinz_, Sep 04 2018