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 A368075 #9 Apr 22 2025 05:21:46 %S A368075 15,144,10045,21945,220077,99008 %N A368075 a(n) is the least n-gonal number that can be expressed as the difference of two positive n-gonal numbers in exactly n ways. %C A368075 The corresponding indices of n-gonal numbers are in A368074. %H A368075 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a> %e A368075 a(3) = 15: 15 = 21 - 6 = 36 - 21 = 120 - 105. %Y A368075 Cf. A086270, A338105, A368041, A368074. %K A368075 nonn,more %O A368075 3,1 %A A368075 _Ilya Gutkovskiy_, Dec 10 2023