A332948 Number of entries in the eighth blocks of all set partitions of [n] when blocks are ordered by increasing lengths.

1, 73, 1666, 31241, 486377, 6638568, 82413787, 961757669, 10756109317, 116409307679, 1228840258412, 12766418662681, 131564790987337, 1352403410824806, 13925656629847559, 144227711099572501, 1508401366805906552, 15986784485974156076, 172225656206792090516

Offset

8,2

Links

Alois P. Heinz, Table of n, a(n) for n = 8..576

Wikipedia, Partition of a set

Maple

b:= proc(n, i, t) option remember; `if`(n=0, [1, 0], `if`(i>n, 0,
      add((p-> p+`if`(t>0 and t-j<1, [0, p[1]*i], 0))(b(n-i*j, i+1,
      max(0, t-j))/j!*combinat[multinomial](n, i$j, n-i*j)), j=0..n/i)))
    end:
a:= n-> b(n, 1, 8)[2]:
seq(a(n), n=8..26);

Crossrefs

Column k=8 of A319298.

Sequence in context: A197216 A197502 A197241 * A224505 A217286 A282784

Adjacent sequences: A332945 A332946 A332947 * A332949 A332950 A332951

Keyword

nonn

Author

Alois P. Heinz, Mar 03 2020

Status

approved