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 A215571 #10 Sep 07 2016 04:01:23 %S A215571 1,139,746192,9212531290,164401445439455,3611684199828856072, %T A215571 90695437030756958966384,2500267880518574604245088816, %U A215571 73839261438738554611424321993670,2299118288652572230673921886739695630,74651909129454094524656449803220566122458 %N A215571 Number of permutations of n indistinguishable copies of 1..6 with every partial sum <= the same partial sum averaged over all permutations. %H A215571 Vaclav Kotesovec, <a href="/A215571/b215571.txt">Table of n, a(n) for n = 0..26</a> %e A215571 a(1) = 139: (1,2,3,4,5,6), (1,2,3,4,6,5), ..., (3,4,2,1,6,5), (3,4,2,5,1,6). %p A215571 b:= proc(l) option remember; local m, n, g; %p A215571 m, n:= nops(l), add(i, i=l); %p A215571 g:= add(i*l[i], i=1..m)-(m+1)/2*(n-1); %p A215571 `if`(n<2, 1, add(`if`(l[i]>0 and i<=g, %p A215571 b(subsop(i=l[i]-1, l)), 0), i=1..m)) %p A215571 end: %p A215571 a:= n-> b([n$6]): %p A215571 seq(a(n), n=0..6); %Y A215571 Row n=6 of A215561. %K A215571 nonn %O A215571 0,2 %A A215571 _Alois P. Heinz_, Aug 16 2012