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A283952 Number of 3Xn 0..1 arrays with no 1 equal to more than three of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element. 1
0, 0, 87, 906, 7988, 69468, 575456, 4604744, 36137513, 279163040, 2128757750, 16067783050, 120264121036, 893798288058, 6602798852295, 48525145143750, 355015663432086, 2587074206224930, 18786624241231104, 135997998678920894 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Row 3 of A283950.

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) -15*a(n-2) +50*a(n-3) -483*a(n-4) -688*a(n-5) -2954*a(n-6) -1998*a(n-7) +1187*a(n-8) +9770*a(n-9) +26575*a(n-10) +21254*a(n-11) -469*a(n-12) -42264*a(n-13) -80523*a(n-14) -54448*a(n-15) +18704*a(n-16) +71312*a(n-17) +57531*a(n-18) +12848*a(n-19) -15198*a(n-20) -17226*a(n-21) -8382*a(n-22) -2048*a(n-23) +107*a(n-24) +234*a(n-25) +59*a(n-26) +4*a(n-27) -4*a(n-28)

EXAMPLE

Some solutions for n=4

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

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

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

CROSSREFS

Cf. A283950.

Sequence in context: A220055 A281806 A128956 * A294907 A093287 A231218

Adjacent sequences:  A283949 A283950 A283951 * A283953 A283954 A283955

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 18 2017

STATUS

approved

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Last modified January 21 15:30 EST 2022. Contains 350479 sequences. (Running on oeis4.)