A283728 - OEIS

A283728

Number of 3Xn 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element.

0, 6, 159, 1088, 7839, 56106, 369328, 2391828, 15258307, 95588636, 592291968, 3636441278, 22144892123, 133969251618, 805895076555, 4824002960360, 28752431241931, 170726461743312, 1010344566340239, 5961242307456936

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OFFSET

1,2

COMMENTS

Row 3 of A283726.

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) -19*a(n-2) -303*a(n-4) +588*a(n-5) +507*a(n-6) +2028*a(n-7) -5758*a(n-8) -5310*a(n-9) +4331*a(n-10) +15486*a(n-11) +7169*a(n-12) -26070*a(n-13) -7596*a(n-14) +7938*a(n-15) +16823*a(n-16) -5350*a(n-17) -11837*a(n-18) +11864*a(n-19) -5720*a(n-20) +1400*a(n-21) -196*a(n-22)

EXAMPLE

Some solutions for n=4

..1..1..1..1. .1..0..1..0. .1..0..0..1. .0..1..0..1. .0..0..0..0

..0..0..0..1. .1..1..1..1. .0..0..1..1. .0..1..1..0. .1..0..1..0

..1..0..0..1. .1..0..0..0. .0..1..1..0. .1..0..0..0. .0..1..1..0

CROSSREFS

Cf. A283726.

Sequence in context: A306496 A282564 A324231 * A030449 A364370 A120277

Adjacent sequences: A283725 A283726 A283727 * A283729 A283730 A283731

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 15 2017

STATUS

approved