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 A374144 #13 Feb 16 2025 08:34:07 %S A374144 81,1105,205427,483031,9402323,6232341,79324200,768459127,2265692766, %T A374144 2413112833,6737406626,150437989675,45319359337,15140186701 %N A374144 a(n) is the smallest number which can be represented as the sum of two distinct nonzero n-gonal numbers in exactly n ways, or -1 if no such number exists. %H A374144 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a> %H A374144 Michael S. Branicky, <a href="/A374144/a374144.py.txt">Python program for A374144</a> %e A374144 a(3) = 81 = 3 + 78 = 15 + 66 = 36 + 45. %o A374144 (Python) # see linked program %Y A374144 Cf. A057145, A093195, A332989, A342326, A350405, A374141, A374142, A374143. %K A374144 nonn,more %O A374144 3,1 %A A374144 _Ilya Gutkovskiy_, Jun 28 2024 %E A374144 a(9)-a(16) from _Michael S. Branicky_, Jun 30 2024