A280212 Number of nX2 0..2 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

1, 2, 26, 92, 307, 1072, 3541, 11834, 38687, 125380, 403369, 1286926, 4082099, 12875608, 40414141, 126308002, 393216967, 1219867372, 3772323793, 11631678006, 35769955803, 109730814592, 335856708581, 1025808464330, 3127008856047

Offset

1,2

Comments

Column 2 of A280217.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +6*a(n-2) -20*a(n-3) -49*a(n-4) +24*a(n-5) +148*a(n-6) +128*a(n-7) -48*a(n-8) -128*a(n-9) -64*a(n-10) for n>14

Example

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

Crossrefs

Cf. A280217.

Sequence in context: A337396 A067204 A202077 * A120551 A120547 A132470

Adjacent sequences: A280209 A280210 A280211 * A280213 A280214 A280215

Keyword

nonn

Author

R. H. Hardin, Dec 29 2016

Status

approved