A281395 Number of nX3 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

0, 10, 131, 438, 1413, 3838, 10226, 26468, 66952, 166702, 409856, 997078, 2406401, 5765066, 13727694, 32525520, 76710590, 180193960, 421829583, 984396802, 2290726469, 5317276304, 12314336174, 28459103594, 65645569873, 151157660144

Offset

1,2

Comments

Column 3 of A281400.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -4*a(n-2) +6*a(n-3) -18*a(n-4) +4*a(n-5) +15*a(n-6) -6*a(n-7) +31*a(n-8) -48*a(n-9) +32*a(n-10) +8*a(n-11) -48*a(n-12) +32*a(n-13) -16*a(n-14) for n>19

Example

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

Crossrefs

Cf. A281400.

Sequence in context: A292119 A113386 A302615 * A268786 A284196 A286723

Adjacent sequences: A281392 A281393 A281394 * A281396 A281397 A281398

Keyword

nonn

Author

R. H. Hardin, Jan 21 2017

Status

approved