A269033 Number of nX6 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

240, 2208, 44760, 785124, 13031664, 208867428, 3266423688, 50155587360, 759280601376, 11364951702132, 168545724611088, 2480433137331636, 36267257458624740, 527333427504496308, 7630684978884541020

Offset: 1

Author

R. H. Hardin, Feb 18 2016

Keywords

• nonn

Comments

Column 6 of A269035.

Examples

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

Links

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

Crossrefs

Cf. A269035.

Formula

Empirical: a(n) = 36*a(n-1) -436*a(n-2) +1854*a(n-3) +340*a(n-4) -19128*a(n-5) +23849*a(n-6) +56184*a(n-7) -108224*a(n-8) -40816*a(n-9) +160400*a(n-10) -34136*a(n-11) -83203*a(n-12) +42628*a(n-13) +6468*a(n-14) -6334*a(n-15) +204*a(n-16) +240*a(n-17) -25*a(n-18) for n>19