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A283545 Number of 4 X n 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors. 1
16, 98, 573, 4089, 25532, 167920, 1094959, 7101809, 46326550, 301306398, 1961384325, 12768156061, 83100368446, 540929424728, 3520893704293, 22917627167529, 149172500835242, 970968632009710, 6320086805449019 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) + 19*a(n-2) + 62*a(n-3) + 24*a(n-4) + 82*a(n-5) - 75*a(n-6) + 50*a(n-7) - 145*a(n-8).
Empirical g.f.: x*(16 + 66*x + 73*x^2 + 89*x^3 + 7*x^4 - 25*x^5 - 95*x^6 - 145*x^7) / (1 - 2*x - 19*x^2 - 62*x^3 - 24*x^4 - 82*x^5 + 75*x^6 - 50*x^7 + 145*x^8). - Colin Barker, Feb 21 2019
EXAMPLE
Some solutions for n=4:
..1..0..0..0. .1..0..0..1. .0..0..0..1. .0..0..0..1. .1..0..0..0
..0..0..0..0. .1..0..0..0. .0..1..0..1. .1..0..1..0. .0..0..0..1
..1..0..0..1. .0..0..0..0. .0..0..0..0. .0..0..0..0. .1..0..0..1
..1..0..1..0. .0..0..1..1. .1..0..0..0. .0..0..0..0. .1..0..0..0
CROSSREFS
Row 4 of A283543.
Sequence in context: A264580 A122102 A214612 * A297684 A344866 A322722
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 10 2017
STATUS
approved

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Last modified May 27 03:56 EDT 2024. Contains 372847 sequences. (Running on oeis4.)