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A268991 Number of n X 4 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once. 1
13, 103, 805, 6009, 43512, 308112, 2144780, 14730784, 100087792, 674045392, 4505925696, 29933341056, 197782652096, 1300744853760, 8519586895104, 55600022810880, 361688403251200, 2346083095244800, 15178387509332992 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 16*a(n-1) - 88*a(n-2) + 200*a(n-3) - 208*a(n-4) + 96*a(n-5) - 16*a(n-6) for n>7.

Empirical g.f.: x*(13 - 105*x + 301*x^2 - 407*x^3 + 312*x^4 - 112*x^5 + 4*x^6) / (1 - 8*x + 12*x^2 - 4*x^3)^2. - Colin Barker, Jan 17 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 4 of A268995.

Sequence in context: A066034 A228213 A220734 * A216179 A240804 A100277

Adjacent sequences:  A268988 A268989 A268990 * A268992 A268993 A268994

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 17 2016

STATUS

approved

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Last modified September 28 06:05 EDT 2021. Contains 347703 sequences. (Running on oeis4.)