A252906 - OEIS

%I #4 Dec 24 2014 16:12:01

%S 1125,6699,42647,288263,1984711,13720545,95366448,664294791,

%T 4628430243,32278030363,225170352448,1570680525096,10958602605331,

%U 76461093301994,533470122592798,3722231877540721,25971571135506891,181212232746263516

%N Number of (n+2)X(2+2) 0..3 arrays with every consecutive three elements in every row and column having exactly 2 distinct values, in every diagonal 1 or 2 distinct values, in every antidiagonal 2 or 3 distinct values, and new values 0 upwards introduced in row major order

%C Column 2 of A252910

%H R. H. Hardin, <a href="/A252906/b252906.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=2

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

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

%e ..1..1..2..1....2..0..2..2....0..1..0..1....0..1..1..0....1..3..1..1

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 24 2014