A281125 Number of nX3 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

1, 28, 574, 5590, 48828, 394202, 3042893, 22772368, 166675727, 1199580226, 8520471567, 59882031330, 417204045166, 2885615431576, 19835570766874, 135626535970070, 923084270635629, 6257223861792470, 42263904928277217

Offset

1,2

Comments

Column 3 of A281129.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -70*a(n-3) -176*a(n-4) -366*a(n-5) -101*a(n-6) +541*a(n-7) +111*a(n-8) -731*a(n-9) -2114*a(n-10) -1900*a(n-11) +3502*a(n-12) +2900*a(n-13) -4597*a(n-14) -2319*a(n-15) +2436*a(n-16) +220*a(n-17) +76*a(n-18) +1492*a(n-19) +672*a(n-20) +160*a(n-21) +192*a(n-22) +64*a(n-23) for n>30

Example

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

Crossrefs

Cf. A281129.

Sequence in context: A145149 A062142 A240800 * A234618 A107397 A053110

Adjacent sequences: A281122 A281123 A281124 * A281126 A281127 A281128

Keyword

nonn

Author

R. H. Hardin, Jan 15 2017

Status

approved