A303957 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 5 king-move adjacent elements, with upper left element zero.

8, 9, 22, 61, 159, 452, 1228, 3334, 9109, 24981, 68361, 186938, 511360, 1399227, 3828333, 10473733, 28654819, 78397711, 214490589, 586827986, 1605511103, 4392547097, 12017651474, 32879305320, 89955066866, 246109662001

Offset

1,1

Comments

Column 4 of A303961.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) -3*a(n-3) +3*a(n-4) -2*a(n-5) -14*a(n-6) +6*a(n-7) +9*a(n-8) -5*a(n-9) +4*a(n-11) -2*a(n-13) for n>17

Example

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

Crossrefs

Cf. A303961.

Sequence in context: A048124 A322637 A322640 * A046258 A074344 A256932

Adjacent sequences: A303954 A303955 A303956 * A303958 A303959 A303960

Keyword

nonn

Author

R. H. Hardin, May 03 2018

Status

approved