A215571 Number of permutations of n indistinguishable copies of 1..6 with every partial sum <= the same partial sum averaged over all permutations.

1, 139, 746192, 9212531290, 164401445439455, 3611684199828856072, 90695437030756958966384, 2500267880518574604245088816, 73839261438738554611424321993670, 2299118288652572230673921886739695630, 74651909129454094524656449803220566122458

Offset: 0

Author

Alois P. Heinz, Aug 16 2012

Keywords

• nonn

Examples

			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).
		

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..26

Crossrefs

Row n=6 of A215561.

Programs

Maple

b:= proc(l) option remember; local m, n, g;
      m, n:= nops(l), add(i, i=l);
      g:= add(i*l[i], i=1..m)-(m+1)/2*(n-1);
     `if`(n<2, 1, add(`if`(l[i]>0 and i<=g,
        b(subsop(i=l[i]-1, l)), 0), i=1..m))
    end:
a:= n-> b([n$6]):
seq(a(n), n=0..6);