A225254 Number of distinct values of the sum of 3 products of two 0..n integers.

1, 4, 12, 25, 43, 67, 95, 130, 169, 215, 267, 324, 385, 454, 527, 606, 692, 784, 880, 983, 1090, 1205, 1325, 1449, 1578, 1716, 1860, 2008, 2162, 2323, 2488, 2661, 2838, 3022, 3210, 3403, 3605, 3813, 4025, 4242, 4464, 4695, 4930, 5173, 5420, 5673, 5933, 6197

Offset: 0

Author

R. H. Hardin, May 04 2013

Keywords

• nonn

Links

• R. H. Hardin, Table of n, a(n) for n = 0..999

Crossrefs

Row 3 of A225252.

Programs

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

Extensions

a(0)=1 prepended by Alois P. Heinz, Oct 13 2023