A283227 Number of n X 3 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, 1, 34, 395, 3996, 37869, 338397, 2903399, 24188526, 196906027, 1573282195, 12379155797, 96158433169, 738796369876, 5622865097337, 42443605420288, 318066721949699, 2368270143804417, 17532717135478046, 129129170044433714

Offset

1,3

Comments

Column 3 of A283232.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -54*a(n-2) -10*a(n-3) -318*a(n-4) +1056*a(n-5) +3892*a(n-6) +15081*a(n-7) +28818*a(n-8) +47074*a(n-9) +42561*a(n-10) +16083*a(n-11) -40047*a(n-12) -76149*a(n-13) -66630*a(n-14) -5493*a(n-15) +53052*a(n-16) +53256*a(n-17) +9505*a(n-18) -26049*a(n-19) -17790*a(n-20) +3537*a(n-21) +5733*a(n-22) +369*a(n-23) -753*a(n-24) -126*a(n-25) +36*a(n-26) +8*a(n-27).

Example

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

Crossrefs

Cf. A283232.

Sequence in context: A271756 A228995 A135243 * A033914 A189452 A159655

Adjacent sequences: A283224 A283225 A283226 * A283228 A283229 A283230

Keyword

nonn

Author

R. H. Hardin, Mar 03 2017

Status

approved