A225259 Number of distinct values of the sum of 2 products of three 0..n integers.

3, 12, 36, 75, 157, 254, 434, 635, 911, 1237, 1734, 2162, 2908, 3611, 4461, 5435, 6734, 7879, 9568, 10964, 12861, 14913, 17438, 19426, 22381, 25251, 28482, 31624, 35879, 39100, 44165, 48267, 53463, 58590, 64476, 69214, 76693, 83132, 90303, 96766

Offset: 1

Author

R. H. Hardin, May 04 2013

Keywords

• nonn

Links

• R. H. Hardin, Table of n, a(n) for n = 1..139

Crossrefs

Row 2 of A225258.

Programs

Python

def a(n):
  zn = list(range(n+1))
  prod3 = list(set(i*j*k for i in zn for j in zn[i:] for k in zn[j:]))
  return len(set(a+b for i, a in enumerate(prod3) for b in prod3[i:]))
print([a(n) for n in range(1, 42)]) # Michael S. Branicky, Mar 12 2021