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 A195799 #6 Jul 22 2025 12:46:27 %S A195799 1,1,3,27,105,1695,284427,11606931 %N A195799 Number of triangular nXnXn 0..2 arrays with all rows and diagonals having the same length having the same sum, with corners zero. %C A195799 Column 2 of A195805 %e A195799 Some solutions for n=5 %e A195799 ......0..........0..........0..........0..........0..........0..........0 %e A195799 .....1.0........1.0........1.1........1.2........0.0........1.2........2.0 %e A195799 ....1.0.1......2.0.2......2.2.2......0.1.0......2.0.2......0.1.0......1.1.1 %e A195799 ...0.0.0.1....0.0.0.1....1.2.2.1....2.1.1.1....0.0.0.0....2.1.1.1....0.1.1.2 %e A195799 ..0.1.1.0.0..0.1.2.0.0..0.1.2.1.0..0.1.0.2.0..0.0.2.0.0..0.1.0.2.0..0.2.1.0.0 %K A195799 nonn %O A195799 1,3 %A A195799 _R. H. Hardin_ Sep 23 2011