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 A072690 #5 Mar 20 2022 23:01:30 %S A072690 0,2,2,0,4,6,6,4,0,6,10,12,12,10,6,0,8,14,18,20,20,18,14,8,0,10,18,24, %T A072690 28,30,30,28,24,18,10,0,12,22,30,36,40,42,42,40,36,30,22,12,0,14,26, %U A072690 36,44,50,54,56,56,54,50,44,36,26,14,0,16,30,42,52,60,66,70,72,72,70,66 %N A072690 a(n) = (n - A048760(n)) * (A048761(n) - n). %C A072690 a(n)=0 iff n is a square. %F A072690 a(n) = A053186(n) * (A072689(n) - A053186(n)). %Y A072690 a(n) = A053186(n) * A068527(n). %K A072690 nonn %O A072690 1,2 %A A072690 _Reinhard Zumkeller_, Jul 02 2002