A304298 Number of nX4 0..1 arrays with every element unequal to 1, 2, 5 or 8 king-move adjacent elements, with upper left element zero.

2, 1, 5, 4, 13, 30, 43, 129, 245, 519, 1254, 2525, 5707, 12749, 27205, 60962, 133639, 292125, 647249, 1418245, 3119874, 6875729, 15098235, 33237465, 73128441, 160782286, 353832779, 778266279, 1711882901, 3766329669, 8284438272

Offset

1,1

Comments

Column 4 of A304302.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +5*a(n-3) -2*a(n-4) +2*a(n-5) -8*a(n-6) -2*a(n-7) -a(n-8) -4*a(n-9) -a(n-10) -2*a(n-12) -a(n-13) -a(n-14) -a(n-15) for n>19

Example

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

Crossrefs

Cf. A304302.

Sequence in context: A120924 A079285 A240607 * A309976 A257516 A346800

Adjacent sequences: A304295 A304296 A304297 * A304299 A304300 A304301

Keyword

nonn

Author

R. H. Hardin, May 10 2018

Status

approved