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A283637 Number of 4Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements. 1
0, 28, 388, 7742, 61592, 700534, 6345928, 54063960, 463390898, 3745175778, 29932577562, 234328588526, 1803842585678, 13723043109600, 103162171803860, 768173607105144, 5671713327162306, 41562268140668656, 302562753480355030 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A283634.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) +45*a(n-2) -34*a(n-3) -1527*a(n-4) -4200*a(n-5) +5806*a(n-6) +79440*a(n-7) +256035*a(n-8) +556862*a(n-9) +773985*a(n-10) +907686*a(n-11) +67578*a(n-12) -154770*a(n-13) -3028137*a(n-14) -564902*a(n-15) -5353965*a(n-16) +3950340*a(n-17) -4944390*a(n-18) +9675900*a(n-19) -5062575*a(n-20) +8559650*a(n-21) -5818125*a(n-22) +3153750*a(n-23) -3048625*a(n-24) for n>26

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A283634.

Sequence in context: A130608 A331353 A177108 * A126921 A035709 A035476

Adjacent sequences:  A283634 A283635 A283636 * A283638 A283639 A283640

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 12 2017

STATUS

approved

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Last modified January 17 23:51 EST 2022. Contains 350410 sequences. (Running on oeis4.)