A281716 Number of 2 X n 0..1 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

2, 3, 7, 14, 29, 61, 126, 265, 553, 1162, 2441, 5141, 10846, 22921, 48529, 102914, 218617, 465133, 991158, 2115193, 4520361, 9673530, 20728009, 44469637, 95515790, 205383337, 442086081, 952519602, 2054191833, 4433875101, 9578060710

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + a(n-2) - 6*a(n-3) - 2*a(n-4) + 4*a(n-5).

Empirical g.f.: x*(2 - 3*x - 4*x^2 + 2*x^3 + 2*x^4) / ((1 - 2*x)*(1 - x - 3*x^2 + 2*x^4)). - Colin Barker, Feb 20 2019

Example

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

Crossrefs

Row 2 of A281715.

Sequence in context: A135258 A034065 A034075 * A192570 A019595 A112884

Adjacent sequences: A281713 A281714 A281715 * A281717 A281718 A281719

Keyword

nonn

Author

R. H. Hardin, Jan 28 2017

Status

approved