login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A372632
Sum over all partitions of n of the number of elements with minimal multiplicity in their partition.
3
0, 1, 2, 4, 6, 9, 16, 21, 33, 47, 67, 90, 134, 172, 242, 321, 434, 558, 761, 961, 1279, 1627, 2112, 2657, 3452, 4292, 5481, 6824, 8619, 10634, 13381, 16389, 20425, 24989, 30864, 37556, 46221, 55912, 68337, 82510, 100262, 120476, 145855, 174562, 210272, 251065
OFFSET
0,3
LINKS
FORMULA
a(n) = Sum_{k=0..A003056(n)} k * A362615(n,k).
MAPLE
b:= proc(n, i, m, t) option remember; `if`(n=0, t,
`if`(i<1, 0, b(n, i-1, m, t)+add(b(n-i*j, i-1, min(j, m),
`if`(j<m, 1, `if`(j=m, t+1, t))), j=1..n/i)))
end:
a:= n-> b(n$3, 0):
seq(a(n), n=0..45);
MATHEMATICA
b[n_, i_, m_, t_] := b[n, i, m, t] = If[n == 0, t,
If[i < 1, 0, b[n, i - 1, m, t] + Sum[b[n - i*j, i - 1, Min[j, m],
If[j < m, 1, If[j == m, t + 1, t]]], {j, 1, n/i}]]];
a[n_] := b[n, n, n, 0];
Table[a[n], {n, 0, 45}] (* Jean-François Alcover, May 10 2024, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 07 2024
STATUS
approved