A280956 Number of nX3 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

4, 42, 241, 1554, 9899, 63085, 402077, 2562733, 16334111, 104108376, 663554669, 4229292041, 26956196587, 171810442122, 1095066516245, 6979614612419, 44485900541127, 283539343806484, 1807191908208865, 11518481171610485

Offset

1,1

Comments

Column 3 of A280961.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +8*a(n-2) +5*a(n-3) +4*a(n-4) -35*a(n-5) +2*a(n-6) +71*a(n-7) -11*a(n-8) -38*a(n-9) +6*a(n-10) -8*a(n-11) -8*a(n-12) for n>16

Example

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

Crossrefs

Cf. A280961.

Sequence in context: A347320 A220835 A157719 * A301943 A219101 A118447

Adjacent sequences: A280953 A280954 A280955 * A280957 A280958 A280959

Keyword

nonn

Author

R. H. Hardin, Jan 11 2017

Status

approved