cp's OEIS Frontend

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

%I A225259 #12 Jul 23 2025 05:23:01
%S A225259 3,12,36,75,157,254,434,635,911,1237,1734,2162,2908,3611,4461,5435,
%T A225259 6734,7879,9568,10964,12861,14913,17438,19426,22381,25251,28482,31624,
%U A225259 35879,39100,44165,48267,53463,58590,64476,69214,76693,83132,90303,96766
%N A225259 Number of distinct values of the sum of 2 products of three 0..n integers.
%H A225259 R. H. Hardin, <a href="/A225259/b225259.txt">Table of n, a(n) for n = 1..139</a>
%o A225259 (Python)
%o A225259 def a(n):
%o A225259   zn = list(range(n+1))
%o A225259   prod3 = list(set(i*j*k for i in zn for j in zn[i:] for k in zn[j:]))
%o A225259   return len(set(a+b for i, a in enumerate(prod3) for b in prod3[i:]))
%o A225259 print([a(n) for n in range(1, 42)]) # _Michael S. Branicky_, Mar 12 2021
%Y A225259 Row 2 of A225258.
%K A225259 nonn
%O A225259 1,1
%A A225259 _R. H. Hardin_, May 04 2013