A241115 Number of nX3 0..3 arrays with no element equal to exactly three horizontal or vertical neighbors, with new values 0..3 introduced in row major order

5, 178, 9918, 587555, 35000157, 2085879115, 124315318217, 7409032909403, 441568937568818, 26316947602316573, 1568456640467509976, 93478023005207665450, 5571171404819117025366, 332034737407500793137773

Offset

1,1

Comments

Column 3 of A241119

Links

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

Formula

Empirical: a(n) = 60*a(n-1) -7*a(n-2) -972*a(n-3) -2112*a(n-4) -2660*a(n-5) +12008*a(n-6) +48742*a(n-7) +35629*a(n-8) -20302*a(n-9) -27711*a(n-10) -65688*a(n-11) -146133*a(n-12) -130104*a(n-13) -24426*a(n-14) +56268*a(n-15) +56538*a(n-16) +13284*a(n-17) -5103*a(n-18) -5346*a(n-19) -1458*a(n-20) for n>21

Example

Some solutions for n=3
..0..1..1....0..1..2....0..0..1....0..0..1....0..1..0....0..1..2....0..1..2
..2..2..2....0..0..2....2..2..2....1..2..2....2..3..2....2..1..0....0..1..0
..3..1..3....1..2..0....0..3..0....2..3..0....0..0..3....2..3..3....1..0..1

Crossrefs

Sequence in context: A157204 A248383 A200796 * A208196 A194571 A210931

Adjacent sequences: A241112 A241113 A241114 * A241116 A241117 A241118

Keyword

nonn

Author

R. H. Hardin, Apr 16 2014

Status

approved