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 A222824 #5 Jul 23 2025 03:06:19 %S A222824 5682,54182,248442,855192,2319872,5617912,11946912,23683432,43615442, %T A222824 76232022,126661082,203564942,314635222,473400002,693921022 %N A222824 Number of idempotent 5X5 0..n matrices. %C A222824 Row 5 of A222821 %e A222824 Some solutions for n=3 %e A222824 ..1..0..0..2..0....0..0..0..0..0....0..0..0..0..0....1..0..0..0..0 %e A222824 ..0..1..2..2..0....0..1..0..0..3....0..0..0..0..0....0..0..0..0..2 %e A222824 ..0..0..0..0..0....2..0..0..1..3....3..1..1..0..0....0..0..0..0..3 %e A222824 ..0..0..0..0..0....2..0..0..1..3....3..2..0..1..0....2..0..0..0..0 %e A222824 ..0..0..2..1..1....0..0..0..0..0....2..1..0..0..1....0..0..0..0..1 %K A222824 nonn %O A222824 1,1 %A A222824 _R. H. Hardin_ Apr 09 2013