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 A195804 #6 Jul 22 2025 12:47:05 %S A195804 1,1,8,512,27412,21779968,479534519840 %N A195804 Number of triangular nXnXn 0..7 arrays with all rows and diagonals having the same length having the same sum, with corners zero. %C A195804 Column 7 of A195805 %e A195804 Some solutions for n=5 %e A195804 ......0..........0..........0..........0..........0..........0..........0 %e A195804 .....1.1........4.0........1.1........2.5........3.0........3.0........6.3 %e A195804 ....0.1.2......0.1.2......0.1.2......7.1.2......5.1.6......5.1.6......1.1.2 %e A195804 ...2.2.0.0....1.2.0.3....2.2.0.0....2.0.5.4....0.3.2.2....0.3.2.2....3.3.2.5 %e A195804 ..0.0.1.2.0..0.3.1.1.0..0.0.1.2.0..0.5.3.3.0..0.3.4.1.0..0.3.4.1.0..0.6.0.4.0 %K A195804 nonn %O A195804 1,3 %A A195804 _R. H. Hardin_ Sep 23 2011