OFFSET
0,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 0..999
PROG
(Python)
from itertools import combinations_with_replacement
def A225254(n): return len({sum(x) for x in combinations_with_replacement({i*j for i in range(n+1) for j in range(i+1)}, 3)}) # Chai Wah Wu, Oct 13 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 04 2013
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Oct 13 2023
STATUS
approved