A332946 Number of entries in the sixth blocks of all set partitions of [n] when blocks are ordered by increasing lengths.

1, 43, 617, 7681, 79756, 741665, 6467891, 54658254, 451897330, 3685879069, 30091146181, 248749105815, 2091117462980, 17933165800591, 157654535847037, 1426401197217090, 13303368764700743, 127934361462621048, 1268098183967052868, 12948542410221048226

Offset

6,2

Links

Alois P. Heinz, Table of n, a(n) for n = 6..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, 6)[2]:
seq(a(n), n=6..25);

Crossrefs

Column k=6 of A319298.

Sequence in context: A060888 A245427 A337214 * A229689 A146979 A337904

Adjacent sequences: A332943 A332944 A332945 * A332947 A332948 A332949

Keyword

nonn

Author

Alois P. Heinz, Mar 03 2020

Status

approved