A281159 Number of nX2 0..1 arrays with no element equal to more than three of its king-move neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 0, 5, 18, 85, 346, 1388, 5454, 21171, 81250, 309019, 1166316, 4372916, 16300940, 60456037, 223201490, 820709441, 3006697550, 10978569420, 39965443098, 145083078903, 525337769138, 1897732902967, 6840395954992, 24606162295316

Offset

1,3

Comments

Column 2 of A281165.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -24*a(n-2) +15*a(n-3) -18*a(n-4) +75*a(n-5) +55*a(n-6) -54*a(n-7) -102*a(n-8) -184*a(n-9) +36*a(n-10) +168*a(n-11) +136*a(n-12) +48*a(n-13) -96*a(n-14) -64*a(n-15)

Example

Some solutions for n=4
..0..0. .0..0. .0..0. .0..0. .0..1. .0..0. .0..1. .0..0. .0..1. .0..1
..1..1. .0..0. .1..1. .0..0. .0..1. .0..0. .1..1. .0..0. .0..0. .0..1
..1..1. .1..0. .1..1. .0..1. .1..1. .1..0. .1..1. .1..0. .0..0. .0..0
..1..1. .0..1. .1..0. .1..1. .1..1. .1..0. .0..0. .1..1. .1..1. .0..0

Crossrefs

Cf. A281165.

Sequence in context: A343165 A141733 A216723 * A357797 A199257 A188206

Adjacent sequences: A281156 A281157 A281158 * A281160 A281161 A281162

Keyword

nonn

Author

R. H. Hardin, Jan 16 2017

Status

approved