A332949 Number of entries in the ninth blocks of all set partitions of [n] when blocks are ordered by increasing lengths.

1, 91, 2531, 56717, 1052130, 17011450, 248006774, 3363718597, 43354519587, 537399621668, 6456347423794, 75743936924077, 874027443321519, 9978667891988711, 113225455087566673, 1281748270131892718, 14527578406583077101, 165413377044356558731

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>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, 9)[2]:
seq(a(n), n=9..26);

Crossrefs

Column k=9 of A319298.

Sequence in context: A118706 A119150 A008394 * A221738 A332913 A133416

Adjacent sequences: A332946 A332947 A332948 * A332950 A332951 A332952

Keyword

nonn

Author

Alois P. Heinz, Mar 03 2020

Status

approved