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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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 12 2017
STATUS
approved

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Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)