A304350 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

3, 9, 13, 27, 60, 123, 280, 729, 2015, 5844, 17796, 55746, 176718, 565998, 1824691, 5895378, 19079961, 61831121, 200450950, 650016786, 2108377349, 6839182152, 22185876476, 71972913726, 233489826816, 757476164734, 2457387441714

Offset

1,1

Comments

Column 3 of A304355.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +8*a(n-3) -14*a(n-4) -12*a(n-5) +12*a(n-6) -39*a(n-7) +6*a(n-8) -14*a(n-9) +81*a(n-10) +28*a(n-11) -71*a(n-12) -53*a(n-13) +51*a(n-14) +27*a(n-15) -20*a(n-16) -2*a(n-17) +2*a(n-18) for n>20

Example

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

Crossrefs

Cf. A304355.

Sequence in context: A107364 A014861 A018407 * A305913 A215443 A304664

Adjacent sequences: A304347 A304348 A304349 * A304351 A304352 A304353

Keyword

nonn

Author

R. H. Hardin, May 11 2018

Status

approved