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 A288148 #10 Feb 16 2025 08:33:47 %S A288148 0,6,108,2598,123750,12994248,3114709914,1730766715308, %T A288148 2248937669398650,6877862090075063484,49790967547432817528562, %U A288148 857275977287938332061154856,35233501393224883314185777947590 %N A288148 Number of (undirected) paths in the n-triangular grid graph. %C A288148 Paths of length zero are not counted here. %H A288148 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GraphPath.html">Graph Path</a> %H A288148 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TriangularGridGraph.html">Triangular Grid Graph</a> %e A288148 a(1) = 6: %e A288148 : o : o : o : o : o : o %e A288148 : : / : \ : / \ : \ : / %e A288148 : o---o : o o : o o : o o : o---o : o---o . %Y A288148 Cf. A020874, A266513, A112675, A112676. %K A288148 nonn,more %O A288148 0,2 %A A288148 _Eric W. Weisstein_, Jun 05 2017 %E A288148 a(7)-a(12) from _Andrew Howroyd_, Jun 07 2017