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 A195801 #6 Jul 22 2025 12:46:43 %S A195801 1,1,5,125,1759,213319 %N A195801 Number of triangular nXnXn 0..4 arrays with all rows and diagonals having the same length having the same sum, with corners zero. %C A195801 Column 4 of A195805 %e A195801 Some solutions for n=5 %e A195801 ......0..........0..........0..........0..........0..........0..........0 %e A195801 .....2.2........3.0........1.3........4.2........4.2........2.1........0.2 %e A195801 ....2.2.0......1.3.1......0.1.0......0.3.2......0.3.3......2.2.0......3.4.2 %e A195801 ...1.1.3.3....0.3.3.3....3.1.1.1....3.4.2.3....4.3.0.3....0.1.3.3....2.2.3.1 %e A195801 ..0.3.1.1.0..0.3.1.0.0..0.1.0.3.0..0.3.1.3.0..0.2.3.3.0..0.3.1.0.0..0.0.4.1.0 %K A195801 nonn %O A195801 1,3 %A A195801 _R. H. Hardin_ Sep 23 2011