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 A241236 #14 Feb 16 2025 08:33:22 %S A241236 0,1,19,99,310,760,1556,2863,4849,7713,11702,17077,24066,33021,44272, %T A241236 58180,75148,95526,119758,148489,181924,220796,265519,316736,375006, %U A241236 441061,515467,598680,691761,795410,909971,1036745,1176108,1329286,1496711,1679852,1879036,2095235 %N A241236 Number of scalene triangles, distinct up to congruence, on a centered hexagonal grid of size n. %C A241236 A centered hexagonal grid of size n is a grid with A003215(n-1) points forming a hexagonal lattice. %H A241236 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HexNumber.html">Hex Number</a>. %H A241236 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ScaleneTriangle.html">Scalene Triangle</a>. %F A241236 a(n) = A241231(n) - A241237(n). %e A241236 For n = 2 the only kind of non-congruent scalene triangles is the following: %e A241236 /. * %e A241236 * . * %e A241236 \. . %Y A241236 Cf. A190313, A241227. %K A241236 nonn %O A241236 1,3 %A A241236 _Martin Renner_, Apr 17 2014 %E A241236 a(7) from _Martin Renner_, May 31 2014 %E A241236 a(8)-a(13) from _Giovanni Resta_, May 31 2014 %E A241236 More terms from _Bert Dobbelaere_, Oct 17 2022