login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

1/8 the number of nX5 0..7 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors
0

%I #6 Mar 31 2012 12:36:04

%S 15,38731,28967421,32611077940,30884279980274

%N 1/8 the number of nX5 0..7 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors

%C Column 5 of A185903

%e Some solutions for 3X5 with a(1,1)=0

%e ..0..4..0..0..4....0..0..6..6..6....0..0..0..2..6....0..0..6..6..0

%e ..0..4..6..0..4....4..4..4..0..0....0..4..4..2..6....4..4..4..0..0

%e ..0..4..6..0..4....0..0..4..5..5....0..0..4..2..6....4..0..0..7..7

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 06 2011