A196900 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,1,0,2 for x=0,1,2,3,4

1, 7, 71, 401, 2975, 20191, 141833, 986015, 6866117, 47832829, 333044999, 2319651781, 16154076631, 112501830469, 783493377407, 5456430897109, 38000064950619, 264641895220837, 1843034804766363, 12835364615219383

Offset

1,2

Comments

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

Column 4 of A196904

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 4*a(n-1) +29*a(n-2) -30*a(n-3) -227*a(n-4) +183*a(n-5) +345*a(n-6) -1223*a(n-7) +1953*a(n-8) +1175*a(n-9) -3050*a(n-10) +1433*a(n-11) +1011*a(n-12) -2381*a(n-13) -297*a(n-14) +1000*a(n-15) +282*a(n-16) -176*a(n-17) -85*a(n-18) +20*a(n-19) +6*a(n-20) -a(n-21)

Example

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

Crossrefs

Sequence in context: A107601 A175863 A196742 * A319963 A198966 A069591

Adjacent sequences: A196897 A196898 A196899 * A196901 A196902 A196903

Keyword

nonn

Author

R. H. Hardin Oct 07 2011

Status

approved