A333066 Number of entries in the ninth blocks of all set partitions of [n] when blocks are ordered by decreasing lengths.

1, 46, 1211, 24047, 401337, 5957407, 81381744, 1046405027, 12866407790, 153103993523, 1780561219354, 20417258320972, 232758457316938, 2658399095977056, 30621521649045981, 357523836553565584, 4243836001737759231, 51265500225372571466, 629904897694885693327

Offset

9,2

Links

Alois P. Heinz, Table of n, a(n) for n = 9..576

Wikipedia, Partition of a set

Maple

b:= proc(n, i, t) option remember; `if`(n=0, [1, 0], `if`(i<1, 0,
      add((p-> p+`if`(t>0 and t-j<1, [0, p[1]*i], 0))(
       combinat[multinomial](n, i$j, n-i*j)/j!*
      b(n-i*j, min(n-i*j, i-1), max(0, t-j))), j=0..n/i)))
    end:
a:= n-> b(n$2, 9)[2]:
seq(a(n), n=9..27);

Crossrefs

Column k=9 of A319375.

Sequence in context: A258464 A320552 A211835 * A261940 A060561 A281321

Adjacent sequences: A333063 A333064 A333065 * A333067 A333068 A333069

Keyword

nonn

Author

Alois P. Heinz, Mar 06 2020

Status

approved