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A283636 Number of 3Xn 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, 6, 37, 639, 2875, 21963, 127635, 693783, 3852792, 20064881, 103580688, 524492026, 2611146243, 12857829918, 62584105607, 301823257243, 1443755263689, 6855724802293, 32346704566179, 151738352019137, 708116512419058 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 3 of A283634.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) +9*a(n-2) -43*a(n-3) -213*a(n-4) +69*a(n-5) +946*a(n-6) +1929*a(n-7) +1017*a(n-8) +2204*a(n-9) +1875*a(n-10) +2487*a(n-11) -2529*a(n-12) +5073*a(n-13) -3762*a(n-14) +2255*a(n-15) -798*a(n-16) +132*a(n-17) -8*a(n-18)

EXAMPLE

Some solutions for n=4

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

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

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

CROSSREFS

Cf. A283634.

Sequence in context: A185236 A041062 A240324 * A211988 A285934 A083373

Adjacent sequences:  A283633 A283634 A283635 * A283637 A283638 A283639

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 12 2017

STATUS

approved

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Last modified January 21 05:57 EST 2022. Contains 350473 sequences. (Running on oeis4.)