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A283226 Number of nX2 0..1 arrays with no 1 equal to more than two of its horizontal and vertical neighbors, with the exception of exactly two elements. 2
0, 0, 1, 6, 49, 272, 1376, 6620, 30552, 137028, 601505, 2595590, 11046025, 46470096, 193602168, 799863880, 3280706728, 13370543368, 54184746441, 218481349414, 876965449193, 3505660028000, 13961692737448, 55415000968548 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Column 2 of A283232.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) -21*a(n-2) -3*a(n-3) +3*a(n-4) +81*a(n-5) +71*a(n-6) +21*a(n-7) -51*a(n-8) -61*a(n-9) -15*a(n-10) +15*a(n-11) +17*a(n-12) +3*a(n-13) -3*a(n-14) -a(n-15)

EXAMPLE

All solutions for n=4

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

..1..1. .1..1. .1..1. .1..1. .1..1. .1..1

..1..1. .1..1. .1..1. .1..1. .1..1. .1..1

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

CROSSREFS

Cf. A283232.

Sequence in context: A048357 A027766 A097299 * A292124 A104170 A098306

Adjacent sequences:  A283223 A283224 A283225 * A283227 A283228 A283229

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 03 2017

STATUS

approved

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Last modified June 19 19:11 EDT 2019. Contains 324222 sequences. (Running on oeis4.)