A283629 Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements.

0, 0, 37, 388, 3729, 28828, 203025, 1325980, 8216341, 48912768, 282293033, 1589466368, 8771503165, 47606031352, 254776347029, 1347286728096, 7051427209337, 36575153581764, 188217385278837, 961810924181084

Offset

1,3

Comments

Column 3 of A283634.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -78*a(n-2) +134*a(n-3) +162*a(n-4) -840*a(n-5) +728*a(n-6) +1398*a(n-7) -3117*a(n-8) +413*a(n-9) +4626*a(n-10) -4056*a(n-11) -2576*a(n-12) +5376*a(n-13) -768*a(n-14) -3200*a(n-15) +1536*a(n-16) +768*a(n-17) -512*a(n-18)

Example

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

Crossrefs

Cf. A283634.

Sequence in context: A178613 A124337 A027944 * A349742 A264626 A201789

Adjacent sequences: A283626 A283627 A283628 * A283630 A283631 A283632

Keyword

nonn

Author

R. H. Hardin, Mar 12 2017

Status

approved