A280213 Number of nX3 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.

0, 26, 158, 886, 4382, 20593, 93326, 410789, 1768582, 7492763, 31338310, 129696524, 531993558, 2165446751, 8755471090, 35192210828, 140712962436, 559989349075, 2219142915606, 8760369870437, 34461931251266, 135134230809249

Offset

1,2

Comments

Column 3 of A280217.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -12*a(n-2) -96*a(n-3) +273*a(n-4) +165*a(n-5) -1237*a(n-6) +1107*a(n-7) +1053*a(n-8) -3215*a(n-9) +2415*a(n-10) +219*a(n-11) -622*a(n-12) -600*a(n-13) +1371*a(n-14) -349*a(n-15) -468*a(n-16) -108*a(n-17) +80*a(n-18) -240*a(n-19) -192*a(n-20) -64*a(n-21) for n>28

Example

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

Crossrefs

Cf. A280217.

Sequence in context: A230906 A232585 A042314 * A200874 A027280 A006354

Adjacent sequences: A280210 A280211 A280212 * A280214 A280215 A280216

Keyword

nonn

Author

R. H. Hardin, Dec 29 2016

Status

approved