A224620 - OEIS

%I #4 Apr 12 2013 07:49:10

%S 23914,19596,24024,26624,28058,28949,36576,48835,63548,79494,96070,

%T 120095,156156,206698,272947,355586,462001,604267,796828,1055426,

%U 1396436,1843643,2432843,3214414,4254348,5635048,7462704,9879362,13077330

%N Number of (n+4)X7 0..2 matrices with each 5X5 subblock idempotent

%C Column 3 of A224625

%H R. H. Hardin, <a href="/A224620/b224620.txt">Table of n, a(n) for n = 1..96</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -a(n-4) -a(n-7) +a(n-8) -a(n-9) +a(n-10) +a(n-12) -a(n-13) for n>17

%e Some solutions for n=2

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Apr 12 2013