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

0,2

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

Row 3 of A225252.

Sequence in context: A008080 A008157 A116668 * A008186 A008264 A000297

Adjacent sequences: A225251 A225252 A225253 * A225255 A225256 A225257

Keyword

nonn

Author

R. H. Hardin, May 04 2013

Extensions

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

Status

approved