A278016 Number of 3Xn 0..2 arrays with every element plus 1 mod 3 equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.

0, 30, 410, 6372, 98410, 1516632, 23376048, 360279838, 5552721246, 85579707940, 1318971923980, 20328262601458, 313303293592114, 4828693685579504, 74420802953575212, 1146988455048830360, 17677617866311586368

Offset

1,2

Comments

Row 3 of A278014.

Links

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

Formula

Empirical: a(n) = 18*a(n-1) -32*a(n-2) -102*a(n-3) -406*a(n-4) +1452*a(n-5) +2596*a(n-6) +2458*a(n-7) -22648*a(n-8) -18454*a(n-9) +18879*a(n-10) +122984*a(n-11) -5236*a(n-12) -144156*a(n-13) -72858*a(n-14) +40286*a(n-15) +58052*a(n-16) +2232*a(n-17) -1856*a(n-18) -4224*a(n-19)

Example

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

Crossrefs

Cf. A278014.

Sequence in context: A260913 A010835 A022722 * A282125 A296917 A255002

Adjacent sequences: A278013 A278014 A278015 * A278017 A278018 A278019

Keyword

nonn

Author

R. H. Hardin, Nov 08 2016

Status

approved