A268908 Number of 5 X n 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 6912, 98496, 1347192, 17194680, 214142760, 2611960344, 31382176824, 372469407912, 4376985056856, 51011490408120, 590386685589432, 6792451934064264, 77748739088317848, 885979967930009496

Offset

1,2

Comments

Row 5 of A268904.

Links

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

Formula

Empirical: a(n) = 32*a(n-1) -384*a(n-2) +2200*a(n-3) -6494*a(n-4) +9016*a(n-5) -816*a(n-6) -14888*a(n-7) +18879*a(n-8) -5464*a(n-9) -7472*a(n-10) +8336*a(n-11) -3648*a(n-12) +768*a(n-13) -64*a(n-14) for n>18.

Example

Some solutions for n=3
..2..2..1. .0..2..2. .2..1..2. .1..0..1. .2..1..2. .0..0..0. .2..1..0
..2..0..1. .1..2..1. .2..1..0. .0..2..2. .0..2..1. .1..0..0. .2..1..0
..1..2..1. .1..0..1. .0..0..1. .2..2..2. .1..2..2. .1..0..0. .2..1..0
..1..0..0. .1..2..2. .1..2..2. .1..2..2. .1..2..2. .0..1..0. .2..1..2
..0..0..0. .1..2..2. .1..1..0. .1..2..2. .2..2..1. .0..1..1. .0..0..0

Crossrefs

Cf. A268904.

Sequence in context: A233223 A106768 A156419 * A192077 A272913 A230468

Adjacent sequences: A268905 A268906 A268907 * A268909 A268910 A268911

Keyword

nonn

Author

R. H. Hardin, Feb 15 2016

Status

approved