A320765 - OEIS

%I #4 Oct 20 2018 18:05:14

%S 1,20,440,9680,220220,5229224,130069940,3392692160,92780281880,

%T 2657929522820,79670485645608,2495398380120360,81558207395885220,

%U 2777643033619233780,98440545801322467600,3625667341827832048176,138601954935720474004950,5492809832014657114548300

%N Number of ordered set partitions of [n] where the maximal block size equals nine.

%H Alois P. Heinz, <a href="/A320765/b320765.txt">Table of n, a(n) for n = 9..426</a>

%F E.g.f.: 1/(1-Sum_{i=1..9} x^i/i!) - 1/(1-Sum_{i=1..8} x^i/i!).

%F a(n) = A276929(n) - A276928(n).

%p b:= proc(n, k) option remember; `if`(n=0, 1, add(

%p       b(n-i, k)*binomial(n, i), i=1..min(n, k)))

%p     end:

%p a:= n-> (k-> b(n, k) -b(n, k-1))(9):

%p seq(a(n), n=9..25);

%Y Column k=9 of A276922.

%Y Cf. A276928, A276929.

%K nonn

%O 9,2

%A _Alois P. Heinz_, Oct 20 2018