OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..150
EXAMPLE
a(2) = 3: [1,1], [1,2], [2,1].
a(3) = 10: [1,1,1], [1,1,2], [1,1,3], [1,2,1], [1,2,2], [1,3,1], [2,1,1], [2,1,2], [2,2,1], [3,1,1].
a(4) = 31: [1,1,1,1], [1,1,1,2], [1,1,1,3], [1,1,1,4], [1,1,2,1], [1,1,2,2], [1,1,2,3], [1,1,3,1], [1,1,3,2], [1,1,4,1], [1,2,1,1], [1,2,1,2], [1,2,1,3], [1,2,2,1], [1,2,3,1], [1,3,1,1], [1,3,1,2], [1,3,2,1], [1,4,1,1], [2,1,1,1], [2,1,1,2], [2,1,1,3], [2,1,2,1], [2,1,3,1], [2,2,1,1], [2,3,1,1], [3,1,1,1], [3,1,1,2], [3,1,2,1], [3,2,1,1], [4,1,1,1].
MAPLE
b:= proc(n, i, s, p) option remember;
`if`(s+n*i<=p, 0, `if`(n=0 or i=1, 1/n!,
add(b(n-j, i-1, s+i*j, p*i^j)/j!, j=0..n)))
end:
a:= n-> b(n$2, 0, 1)*n!:
seq(a(n), n=0..44);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 27 2023
STATUS
approved