A225261 Number of distinct values of the sum of 4 products of three 0..n integers.

5, 28, 90, 205, 409, 694, 1123, 1668, 2396, 3298, 4442, 5741, 7410, 9266, 11443, 13937, 16857, 20031, 23746, 27694, 32236, 37143, 42619, 48390, 55021, 62036, 69617, 77815, 86744, 96000, 106372, 117136, 128823, 141110, 154192, 167871, 182867, 198285

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..138

Prog

(Python)
from itertools import combinations_with_replacement as mc
def a(n):
  prods = set(a*b*c for a, b, c in mc(range(n+1), 3))
  return len(set(sum(p) for p in mc(prods, 4)))
print([a(n) for n in range(1, 11)]) # Michael S. Branicky, May 28 2021

Crossrefs

Cf. A027426.

Row 4 of A225258.

Sequence in context: A316560 A275709 A257093 * A088727 A027016 A034582

Adjacent sequences: A225258 A225259 A225260 * A225262 A225263 A225264

Keyword

nonn

Author

R. H. Hardin, May 04 2013

Status

approved