A224683 - OEIS

%I #4 Apr 15 2013 07:42:54

%S 5682,2351,2662,3465,4405,5385,6713,8897,12393,17893,25853,36869,

%T 52253,74230,106404,154071,224107,325892,472847,684866,991959,1438581,

%U 2089095,3035865,4411494,6407917,9304859,13510805,19621025,28500115,41401620

%N Number of (n+4)X5 0..1 matrices with each 5X5 subblock idempotent

%C Column 1 of A224690

%H R. H. Hardin, <a href="/A224683/b224683.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-4) +2*a(n-5) -a(n-7) -a(n-9) +a(n-10) -a(n-11) +a(n-12) for n>18

%e Some solutions for n=2

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Apr 15 2013