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 A222822 #6 Jul 23 2025 03:06:04 %S A222822 50,122,218,344,488,668,860,1088,1334,1610,1898,2234,2570,2942,3338, %T A222822 3764,4196,4676,5156,5684,6224,6788,7364,8000,8630,9290,9974,10694, %U A222822 11414,12194,12962,13778,14606,15458,16334,17264,18176,19124,20096,21116,22124 %N A222822 Number of idempotent 3X3 0..n matrices. %C A222822 Row 3 of A222821 %H A222822 R. H. Hardin, <a href="/A222822/b222822.txt">Table of n, a(n) for n = 1..81</a> %e A222822 Some solutions for n=3 %e A222822 ..0..0..0....1..0..0....1..0..0....1..0..0....1..0..0....0..0..0....0..0..0 %e A222822 ..0..0..0....1..0..0....2..0..0....0..1..0....2..0..3....1..1..1....0..1..0 %e A222822 ..0..0..0....0..0..0....0..0..1....2..1..0....0..0..1....0..0..0....0..1..0 %K A222822 nonn %O A222822 1,1 %A A222822 _R. H. Hardin_ Apr 09 2013