A281134 Number of nX3 0..2 arrays with no element equal to more than one of its king-move neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

1, 24, 297, 1046, 3460, 10790, 32692, 96454, 279958, 801574, 2269012, 6364810, 17720024, 49016062, 134841796, 369185826, 1006589456, 2734396414, 7403739804, 19988032370, 53820207056, 144572702206, 387513485500, 1036641811138

Offset

1,2

Comments

Column 3 of A281139.

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) +8*a(n-3) -18*a(n-4) +4*a(n-5) -12*a(n-6) -4*a(n-7) +7*a(n-8) -16*a(n-9) +20*a(n-10) -4*a(n-11) -4*a(n-12) +8*a(n-13) -4*a(n-14) for n>19

Example

Some solutions for n=4
..0..0..1. .0..0..1. .0..1..0. .0..1..1. .0..1..2. .0..1..2. .0..1..0
..2..1..2. .1..2..2. .0..2..1. .2..0..2. .2..1..2. .2..1..2. .1..0..2
..2..0..0. .1..0..1. .1..2..0. .1..1..0. .2..0..0. .0..1..0. .2..0..2
..2..1..2. .0..2..0. .0..1..2. .0..2..2. .0..1..2. .0..2..2. .2..1..1

Crossrefs

Cf. A281139.

Sequence in context: A086941 A187028 A186966 * A128598 A161524 A161931

Adjacent sequences: A281131 A281132 A281133 * A281135 A281136 A281137

Keyword

nonn

Author

R. H. Hardin, Jan 15 2017

Status

approved