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A224118 T(n,k)=Number of idempotent n X n 0..k matrices of rank n-2.

%I A224118 #7 Jun 02 2025 08:30:31
%S A224118 0,0,1,0,1,27,0,1,69,282,0,1,123,1434,2050,0,1,195,4182,20810,12405,0,
%T A224118 1,273,9762,103050,260235,67557,0,1,375,19110,368130,2273505,3037167,
%U A224118 344708,0,1,477,34602,1042030,12775065,47922021,34229076,1686132,0,1,603
%N A224118 T(n,k)=Number of idempotent n X n 0..k matrices of rank n-2.
%C A224118 Table starts
%C A224118 .......0........0........0.........0........0.......0.....0...0.0.0
%C A224118 .......1........1........1.........1........1.......1.....1...1.1
%C A224118 ......27.......69......123.......195......273.....375...477.603
%C A224118 .....282.....1434.....4182......9762....19110...34602.56982
%C A224118 ....2050....20810...103050....368130..1042030.2563150
%C A224118 ...12405...260235..2273505..12775065.52968495
%C A224118 ...67557..3037167.47922021.427616679
%C A224118 ..344708.34229076
%C A224118 .1686132
%H A224118 R. H. Hardin, <a href="/A224118/b224118.txt">Table of n, a(n) for n = 1..52</a>
%e A224118 Some solutions for n=3 k=4
%e A224118 ..1..0..0....1..3..0....1..3..0....0..3..3....0..0..0....0..1..0....0..0..1
%e A224118 ..1..0..0....0..0..0....0..0..0....0..1..1....0..0..1....0..1..0....0..0..3
%e A224118 ..3..0..0....1..3..0....0..0..0....0..0..0....0..0..1....0..0..0....0..0..1
%Y A224118 Row 3 is A224525
%Y A224118 Row 4 is A224115
%K A224118 nonn,tabl
%O A224118 1,6
%A A224118 _R. H. Hardin_ Apr 09 2013