OFFSET
0,3
COMMENTS
|lambda| is the number of parts in lambda and |{lambda}| is the number of distinct parts.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
MAPLE
b:= proc(n, i, p, d) option remember; `if`(n=0, binomial(p, d),
`if`(i<1, 0, add(b(n-i*j, i-1, p+j, `if`(j=0, d, d+1)), j=0..n/i)))
end:
a:= n-> b(n$2, 0$2):
seq(a(n), n=0..50);
MATHEMATICA
b[n_, i_, p_, d_] := b[n, i, p, d] = If[n == 0, Binomial[p, d],
If[i<1, 0, Sum[b[n-i*j, i-1, p+j, If[j == 0, d, d+1]], {j, 0, n/i}]]];
a[n_] := b[n, n, 0, 0];
Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Aug 01 2021, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Nov 18 2020
STATUS
approved