A297015 Number of nX3 0..1 arrays with each 1 adjacent to 3, 4 or 6 king-move neighboring 1s.

1, 3, 8, 14, 39, 135, 400, 1310, 4481, 15005, 50813, 173538, 590268, 2009778, 6857427, 23374979, 79672060, 271719009, 926494874, 3158768148, 10771237589, 36728205113, 125230802047, 427013571111, 1456037283696, 4964723542111

Offset

1,2

Comments

Column 3 of A297020.

Links

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

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) +22*a(n-3) -3*a(n-4) -80*a(n-5) -161*a(n-6) -18*a(n-7) +288*a(n-8) +466*a(n-9) +118*a(n-10) -275*a(n-11) -312*a(n-12) +63*a(n-13) +36*a(n-14) -124*a(n-15) -134*a(n-16) +22*a(n-17) +68*a(n-18) -17*a(n-19) -20*a(n-20)

Example

Some solutions for n=7
..0..1..1. .1..1..0. .0..0..0. .0..0..0. .0..1..1. .0..1..0. .0..1..1
..1..1..1. .1..1..0. .0..0..0. .0..1..0. .1..1..1. .1..1..1. .1..1..1
..1..1..0. .0..1..0. .1..1..0. .1..1..1. .1..1..0. .1..1..1. .1..0..1
..0..1..1. .0..1..1. .1..1..0. .0..1..0. .0..0..0. .0..1..0. .0..1..1
..1..1..1. .1..0..1. .1..0..0. .0..0..1. .0..1..0. .1..1..1. .0..1..0
..1..1..0. .1..1..1. .0..1..1. .0..1..1. .1..1..1. .0..1..0. .0..1..1
..0..0..0. .0..1..1. .0..1..1. .0..1..1. .0..1..0. .0..0..0. .0..1..1

Crossrefs

Cf. A297020.

Sequence in context: A005735 A208436 A372217 * A135872 A242245 A045263

Adjacent sequences: A297012 A297013 A297014 * A297016 A297017 A297018

Keyword

nonn

Author

R. H. Hardin, Dec 23 2017

Status

approved