OFFSET
0,4
FORMULA
G.f.: Product_{k>=1} (1-x^(k*(k^2+1)))/(1-x^k).
EXAMPLE
n | | a(n)
----+--------------------------------+------
1 | 1 | 1
2 | 2 | 1
3 | 3, 2+1 | 2
4 | 4, 3+1, 2+2 | 3
5 | 5, 4+1, 3+2, 2+2+1 | 4
6 | 6, 5+1, 4+2, 3+3, 3+2+1, 2+2+2 | 6
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 03 2018
STATUS
approved