A304013 Number of nX2 0..1 arrays with every element unequal to 1, 2, 3 or 5 king-move adjacent elements, with upper left element zero.

1, 7, 16, 45, 120, 333, 928, 2613, 7400, 21053, 60080, 171845, 492280, 1411789, 4051904, 11635413, 33424648, 96042845, 276020944, 793366629, 2280573208, 6556026349, 18847591392, 54185601013, 155783294760, 447882509949

Offset

1,2

Comments

Column 2 of A304019.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +5*a(n-2) -2*a(n-3) -12*a(n-4) -8*a(n-5) for n>6

Example

Some solutions for n=5
..0..0. .0..0. .0..0. .0..1. .0..1. .0..0. .0..0. .0..1. .0..1. .0..0
..0..1. .1..0. .1..0. .0..0. .1..1. .1..0. .1..0. .1..1. .0..0. .0..1
..0..0. .1..1. .1..1. .1..0. .0..0. .1..1. .0..0. .0..0. .0..1. .0..0
..1..1. .0..1. .0..0. .1..1. .0..1. .0..0. .1..0. .0..0. .1..1. .0..0
..0..1. .1..1. .1..0. .0..0. .0..0. .0..1. .1..1. .0..1. .1..0. .1..0

Crossrefs

Cf. A304019.

Sequence in context: A024625 A055553 A066009 * A037241 A154141 A173661

Adjacent sequences: A304010 A304011 A304012 * A304014 A304015 A304016

Keyword

nonn

Author

R. H. Hardin, May 04 2018

Status

approved