A278282 Number of 3Xn 0..1 arrays with every element both equal and not equal to some elements at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.

0, 5, 25, 122, 661, 3723, 20736, 115446, 643201, 3583987, 19968771, 111259772, 619906272, 3453935575, 19244300244, 107223525884, 597417624393, 3328633543713, 18546157153693, 103333677917171, 575744553924121

Offset

1,2

Comments

Row 3 of A278280.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +14*a(n-2) +3*a(n-3) -a(n-4) -20*a(n-5) -65*a(n-6) +20*a(n-7) +53*a(n-8) +10*a(n-9) +55*a(n-10) +12*a(n-11) -3*a(n-12) +13*a(n-13) -8*a(n-14) +3*a(n-15) -a(n-16)

Example

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

Crossrefs

Cf. A278280.

Sequence in context: A275906 A249454 A250347 * A086093 A171279 A231636

Adjacent sequences: A278279 A278280 A278281 * A278283 A278284 A278285

Keyword

nonn

Author

R. H. Hardin, Nov 16 2016

Status

approved