A184780 - OEIS

%I #6 Mar 31 2012 12:36:01

%S 12792,260268,5299212,107810856,2193592920,44633574216,908160565032,

%T 18478374229416,375980327644488,7650088026679752,155656671056370024,

%U 3167153029248451944,64442199825855185928,1311208229754332950152

%N Number of (n+2)X3 0..2 arrays with each 3X3 subblock nonsingular

%C Column 1 of A184784

%H R. H. Hardin, <a href="/A184780/b184780.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=4*a(n-1)+123*a(n-2)+2670*a(n-3)+22675*a(n-4)+159996*a(n-5)+683337*a(n-6)+2159142*a(n-7)+2203254*a(n-8)-10791668*a(n-9)-60946844*a(n-10)-139654560*a(n-11)+113218448*a(n-12)+853157504*a(n-13)+1692141376*a(n-14)-914983808*a(n-15)-12472539648*a(n-16)+666559488*a(n-17)+33631735808*a(n-18)-11806212096*a(n-19)-31261982720*a(n-20)+19818086400*a(n-21)

%e Some solutions for 4X3

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 21 2011