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A207256 Number of 5 X n 0..1 arrays avoiding 0 0 1 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically. 1
16, 256, 1232, 3776, 9072, 18688, 34608, 59264, 95568, 146944, 217360, 311360, 434096, 591360, 789616, 1036032, 1338512, 1705728, 2147152, 2673088, 3294704, 4024064, 4874160, 5858944, 6993360, 8293376, 9776016, 11459392, 13362736 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 5 of A207254.

LINKS

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

FORMULA

Empirical: a(n) = (4/15)*n^5 + (32/3)*n^4 + (44/3)*n^3 - (32/3)*n^2 + (16/15)*n.

Conjectures from Colin Barker, Jun 21 2018: (Start)

G.f.: 16*x*(1 + 10*x - 4*x^2 - 6*x^3 + x^4) / (1 - x)^6.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.

(End)

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A207254.

Sequence in context: A207521 A207920 A208700 * A207951 A207860 A207810

Adjacent sequences:  A207253 A207254 A207255 * A207257 A207258 A207259

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 16 2012

STATUS

approved

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Last modified October 18 08:27 EDT 2021. Contains 348067 sequences. (Running on oeis4.)