cp's OEIS Frontend

A320740 Number of partitions of n with nine sorts of part 1 which are introduced in ascending order.

%I A320740 #8 Dec 07 2020 09:03:59
%S A320740 1,1,3,7,20,63,233,966,4454,22404,121615,706306,4360204,28452601,
%T A320740 195263881,1402218667,10482569938,81153069799,647261864569,
%U A320740 5292447172261,44165731426846,374675276723042,3220404743013997,27967105952549269,244844437773618386
%N A320740 Number of partitions of n with nine sorts of part 1 which are introduced in ascending order.
%H A320740 Alois P. Heinz, <a href="/A320740/b320740.txt">Table of n, a(n) for n = 0..1053</a>
%p A320740 b:= proc(n, i) option remember; `if`(n=0 or i<2, add(
%p A320740       Stirling2(n, j), j=0..9), add(b(n-i*j, i-1), j=0..n/i))
%p A320740     end:
%p A320740 a:= n-> b(n$2):
%p A320740 seq(a(n), n=0..40);
%t A320740 b[n_, i_] := b[n, i] = If[n == 0 || i < 2, Sum[StirlingS2[n, j], {j, 0, 9}], Sum[b[n - i j, i - 1], {j, 0, n/i}]];
%t A320740 a[n_] := b[n, n];
%t A320740 a /@ Range[0, 40] (* _Jean-François Alcover_, Dec 07 2020, after _Alois P. Heinz_ *)
%Y A320740 Column k=9 of A292745.
%K A320740 nonn
%O A320740 0,3
%A A320740 _Alois P. Heinz_, Oct 20 2018