A283226 Number of n X 2 0..1 arrays with no 1 equal to more than two of its horizontal and vertical neighbors, with the exception of exactly two elements.

0, 0, 1, 6, 49, 272, 1376, 6620, 30552, 137028, 601505, 2595590, 11046025, 46470096, 193602168, 799863880, 3280706728, 13370543368, 54184746441, 218481349414, 876965449193, 3505660028000, 13961692737448, 55415000968548

Offset

1,4

Comments

Column 2 of A283232.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -21*a(n-2) -3*a(n-3) +3*a(n-4) +81*a(n-5) +71*a(n-6) +21*a(n-7) -51*a(n-8) -61*a(n-9) -15*a(n-10) +15*a(n-11) +17*a(n-12) +3*a(n-13) -3*a(n-14) -a(n-15).

Example

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

Crossrefs

Cf. A283232.

Sequence in context: A048357 A027766 A097299 * A292124 A104170 A098306

Adjacent sequences: A283223 A283224 A283225 * A283227 A283228 A283229

Keyword

nonn

Author

R. H. Hardin, Mar 03 2017

Status

approved