A222822 - OEIS

%I #4 Apr 09 2013 10:21:46

%S 50,122,218,344,488,668,860,1088,1334,1610,1898,2234,2570,2942,3338,

%T 3764,4196,4676,5156,5684,6224,6788,7364,8000,8630,9290,9974,10694,

%U 11414,12194,12962,13778,14606,15458,16334,17264,18176,19124,20096,21116,22124

%N Number of idempotent 3X3 0..n matrices

%C Row 3 of A222821

%H R. H. Hardin, <a href="/A222822/b222822.txt">Table of n, a(n) for n = 1..81</a>

%e Some solutions for n=3

%e ..0..0..0....1..0..0....1..0..0....1..0..0....1..0..0....0..0..0....0..0..0

%e ..0..0..0....1..0..0....2..0..0....0..1..0....2..0..3....1..1..1....0..1..0

%e ..0..0..0....0..0..0....0..0..1....2..1..0....0..0..1....0..0..0....0..1..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Apr 09 2013