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”).

A196951
Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 2,1,3,4,0 for x=0,1,2,3,4
0
1, 5, 26, 492, 23956, 3166711, 1147966466, 1139814557483, 3088781045935076, 22873717950695283084, 463109589156291297397232, 25624345402722028725104412700, 3874850344967499961830383314013710
OFFSET
1,2
COMMENTS
Every 0 is next to 0 2's, every 1 is next to 1 1's, every 2 is next to 2 3's, every 3 is next to 3 4's, every 4 is next to 4 0's
Diagonal of A196957
EXAMPLE
Some solutions for n=4
..0..0..1..1....0..1..0..0....1..1..0..0....1..1..0..1....1..0..0..0
..0..0..0..0....0..1..0..1....0..0..4..0....0..0..0..1....1..0..1..1
..1..0..0..1....0..0..0..1....1..1..0..0....0..0..4..0....0..0..0..0
..1..0..0..1....0..0..0..0....0..0..0..0....1..1..0..0....0..1..1..0
CROSSREFS
Sequence in context: A140423 A324419 A090644 * A379689 A156217 A156216
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 08 2011
STATUS
approved