OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
PROG
(PARI) a(n) = #Set(Vec(prod(k=1, n, (1-x^k)^3)));
(Python)
from collections import Counter
def A369790(n):
c = {0:1}
for k in range(1, n+1):
d = Counter(c)
for j in c:
a = c[j]
d[j+k] -= 3*a
d[j+2*k] += 3*a
d[j+3*k] -= a
c = d
return len(set(c.values()))+int(max(c)+1>len(c)) # Chai Wah Wu, Feb 01 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 01 2024
STATUS
approved