A196985 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,3,4,1,0 for x=0,1,2,3,4.

1, 5, 25, 113, 547, 2499, 11647, 54845, 256395, 1198317, 5607683, 26243839, 122783657, 574447047, 2687794239, 12575875245, 58839924859, 275301009225, 1288087194957, 6026735743519, 28198022800317, 131933577537561

Offset

1,2

Comments

Every 0 is next to 0 2's, every 1 is next to 1 3's, every 2 is next to 2 4's, every 3 is next to 3 1's, every 4 is next to 4 0's

Column 4 of A196989

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) +25*a(n-3) +33*a(n-4) +a(n-5) -135*a(n-6) -117*a(n-7) +48*a(n-8) +141*a(n-9) -24*a(n-10) -135*a(n-11) -106*a(n-12) +18*a(n-13) +45*a(n-14) +27*a(n-15) +6*a(n-16) +2*a(n-17)

Example

Some solutions for n=5
..0..0..0..0....1..3..1..0....1..0..0..0....1..3..1..1....1..1..3..1
..0..0..0..0....0..1..0..0....3..1..0..1....0..1..1..3....3..1..1..1
..0..4..0..0....0..1..0..0....1..0..1..3....0..0..0..1....1..1..1..3
..0..0..1..0....0..3..1..0....0..0..1..1....0..1..3..1....1..3..0..1
..0..1..3..1....0..1..0..0....0..1..3..1....0..0..1..0....0..1..0..0

Crossrefs

Sequence in context: A183926 A365581 A092440 * A124534 A369769 A261383

Adjacent sequences: A196982 A196983 A196984 * A196986 A196987 A196988

Keyword

nonn

Author

R. H. Hardin, Oct 08 2011

Status

approved