A281567 Number of 5Xn 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 57, 4172, 15508, 50510, 119319, 243040, 458646, 836348, 1499031, 2639156, 4598088, 7964505, 13723351, 23542072, 40224454, 68484867, 116236613, 196696242, 331912800, 558609817, 937824339, 1570843506, 2625457910, 4379204675

Offset

1,2

Comments

Row 5 of A281563.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -15*a(n-2) +23*a(n-3) -30*a(n-4) +39*a(n-5) -49*a(n-6) +57*a(n-7) -57*a(n-8) +52*a(n-9) -48*a(n-10) +42*a(n-11) -34*a(n-12) +24*a(n-13) -15*a(n-14) +10*a(n-15) -6*a(n-16) +3*a(n-17) -a(n-18) for n>28

Example

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

Crossrefs

Cf. A281563.

Sequence in context: A218370 A218636 A218240 * A012165 A209512 A132783

Adjacent sequences: A281564 A281565 A281566 * A281568 A281569 A281570

Keyword

nonn

Author

R. H. Hardin, Jan 24 2017

Status

approved