OFFSET
0,5
COMMENTS
Also the number of distinct nonzero entries in row n of A008284.
EXAMPLE
Row n = 9 of A008284 is (1, 4, 7, 6, 5, 3, 2, 1, 1), which has union {1,2,3,4,5,6,7}, so a(9) = 7.
MAPLE
b:= proc(n, i) option remember; `if`(n=0 or i=1, x^n,
b(n, i-1)+expand(x*b(n-i, min(n-i, i))))
end:
a:= n-> nops({coeffs(b(n$2))}):
seq(a(n), n=0..90); # Alois P. Heinz, Feb 23 2024
MATHEMATICA
Table[Length[Union[Table[Length[IntegerPartitions[n, {k}]], {k, n}]]], {n, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 07 2019
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Feb 23 2024
STATUS
approved