A280598 Number of nX2 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

2, 7, 18, 50, 138, 383, 1063, 2951, 8193, 22748, 63161, 175370, 486925, 1351977, 3753848, 10422792, 28939529, 80352400, 223103432, 619460544, 1719970697, 4775605529, 13259765537, 36816563059, 102223475346, 283829832107

Offset

1,1

Comments

Column 2 of A280604.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A280604.

Sequence in context: A074141 A122931 A094976 * A006869 A099626 A261331

Adjacent sequences: A280595 A280596 A280597 * A280599 A280600 A280601

Keyword

nonn

Author

R. H. Hardin, Jan 06 2017

Status

approved