A229248 Number of set partitions of {1,...,n} with largest set of size 6.

1, 7, 56, 420, 3150, 24024, 187110, 1497210, 12321309, 104379275, 910501592, 8176340536, 75557540604, 718108992888, 7015008076980, 70388350377492, 724955013327237, 7658820319677219, 82939240748756392, 920067296840668900, 10448713239329294930

Offset

6,2

Links

Alois P. Heinz, Table of n, a(n) for n = 6..500

Formula

E.g.f.: exp(Sum_{j=1..6} x^j/j!) - exp(Sum_{j=1..5} x^j/j!).

Maple

G:= proc(n, k) option remember; local j; if k>n then G(n, n)
      elif n=0 then 1 elif k<1 then 0 else G(n-k, k);
      for j from k-1 to 1 by -1 do %*(n-j)/j +G(n-j, k) od; % fi
    end:
a:= n-> G(n, 6)-G(n, 5):
seq(a(n), n=6..30);

Crossrefs

Column k=6 of A080510.

Sequence in context: A343364 A092318 A092315 * A242159 A057090 A156362

Adjacent sequences: A229245 A229246 A229247 * A229249 A229250 A229251

Keyword

nonn

Author

Alois P. Heinz, Sep 17 2013

Status

approved