A224682 - OEIS

%I #5 Apr 15 2013 07:41:50

%S 5682,1312,1636,2166,2700,3158,4572,7006,10366,14544,19462,26588,

%T 37294,52826,74314,102814,141460,195148,270382,375154,518878,715182,

%U 984104,1354110,1863992,2564712,3524856,4838762,6637124,9099956,12471878

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

%C Diagonal of A224690

%H R. H. Hardin, <a href="/A224682/b224682.txt">Table of n, a(n) for n = 1..33</a>

%F Empirical: a(n) = 6*a(n-1) -15*a(n-2) +20*a(n-3) -15*a(n-4) +9*a(n-5) -16*a(n-6) +30*a(n-7) -30*a(n-8) +15*a(n-9) -6*a(n-10) +12*a(n-11) -18*a(n-12) +12*a(n-13) -3*a(n-14) +a(n-15) -3*a(n-16) +3*a(n-17) -a(n-18) for n>22

%e Some solutions for n=2

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Apr 15 2013