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A297096 Number of n X 2 0..1 arrays with no 1 adjacent to 4 king-move neighboring 1s. 1
4, 16, 58, 216, 808, 3016, 11264, 42080, 157192, 587200, 2193552, 8194256, 30610528, 114348992, 427163264, 1595715392, 5960970560, 22267862080, 83184051328, 310743185408, 1160815393920, 4336353754624, 16198927050240, 60512876123648 (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) = 4*a(n-1) - 2*a(n-2) + 6*a(n-3) - 8*a(n-4) - 4*a(n-6).

Empirical g.f.: 2*x*(2 + x^2 - 4*x^3 - 2*x^4 - 2*x^5) / (1 - 4*x + 2*x^2 - 6*x^3 + 8*x^4 + 4*x^6). - Colin Barker, Feb 26 2019

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

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

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

CROSSREFS

Column 2 of A297102.

Sequence in context: A134762 A207276 A047123 * A330791 A032094 A282083

Adjacent sequences:  A297093 A297094 A297095 * A297097 A297098 A297099

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 25 2017

STATUS

approved

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Last modified September 22 06:01 EDT 2021. Contains 347605 sequences. (Running on oeis4.)