This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A225261 #10 May 28 2021 23:02:28 %S A225261 5,28,90,205,409,694,1123,1668,2396,3298,4442,5741,7410,9266,11443, %T A225261 13937,16857,20031,23746,27694,32236,37143,42619,48390,55021,62036, %U A225261 69617,77815,86744,96000,106372,117136,128823,141110,154192,167871,182867,198285 %N A225261 Number of distinct values of the sum of 4 products of three 0..n integers. %H A225261 R. H. Hardin, <a href="/A225261/b225261.txt">Table of n, a(n) for n = 1..138</a> %o A225261 (Python) %o A225261 from itertools import combinations_with_replacement as mc %o A225261 def a(n): %o A225261 prods = set(a*b*c for a, b, c in mc(range(n+1), 3)) %o A225261 return len(set(sum(p) for p in mc(prods, 4))) %o A225261 print([a(n) for n in range(1, 11)]) # _Michael S. Branicky_, May 28 2021 %Y A225261 Cf. A027426. %Y A225261 Row 4 of A225258. %K A225261 nonn %O A225261 1,1 %A A225261 _R. H. Hardin_, May 04 2013