A185821 - OEIS

%I #6 Mar 31 2012 12:36:03

%S 9,5680,1266624,378212944,100480040192,28043363244452,

%T 7662203273902712,2112817100467905536,580282378007177354752,

%U 159650092398206756238532,43890600560593534666234904,12070254095603726713513018032

%N 1/5 the number of nX5 0..4 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors

%C Column 5 of A185825

%e Some solutions for 4X5 with a(1,1)=0

%e ..0..0..0..2..2....0..0..4..4..0....0..0..3..3..2....0..0..3..3..2

%e ..0..1..0..4..4....0..1..3..4..0....0..1..3..3..2....0..1..0..0..2

%e ..0..1..0..3..3....0..1..3..3..4....0..1..0..2..4....0..1..0..2..4

%e ..0..0..0..1..1....0..0..0..0..4....0..0..0..2..4....0..0..0..2..4

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 05 2011