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A206790 Number of nX1 0..3 arrays avoiding the pattern z z+1 z in any row, column, diagonal or antidiagonal 5
4, 16, 61, 232, 883, 3361, 12793, 48694, 185344, 705475, 2685250, 10220869, 38903701, 148079185, 563633908, 2145360148, 8165885869, 31081817236, 118306743223, 450311041525, 1714019240113, 6524072662150, 24832582450012 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A206797

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) -a(n-2) +a(n-3).

Empirical: G.f.: -x*(4+x^2) / ( -1+4*x-x^2+x^3 ). - R. J. Mathar, Jul 17 2014

EXAMPLE

Some solutions for n=4

..1....2....2....0....1....1....2....1....0....1....3....1....0....1....2....1

..3....3....0....3....1....3....2....3....2....3....0....0....1....0....0....0

..2....3....1....1....0....2....1....0....2....3....3....1....1....0....1....1

..1....0....1....2....3....2....0....1....1....1....1....3....3....0....2....1

CROSSREFS

Sequence in context: A133161 A103820 A206570 * A283858 A283409 A192468

Adjacent sequences:  A206787 A206788 A206789 * A206791 A206792 A206793

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 12 2012

STATUS

approved

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Last modified December 3 05:29 EST 2020. Contains 338899 sequences. (Running on oeis4.)