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A184756 Half the number of n X 4 binary arrays with no 1 having an adjacent 1 both above and to its left. 2
8, 89, 1056, 12397, 145778, 1713803, 20148584, 236878817, 2784890782, 32740859687, 384921344068, 4525368067837, 53202963328218, 625486206737315, 7353594054643744, 86453298151112665, 1016397248157274582 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A184761.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 8*a(n-1) + 39*a(n-2) + 58*a(n-3) + 32*a(n-4).

Empirical g.f.: x*(8 + 25*x + 32*x^2 + 14*x^3) / (1 - 8*x - 39*x^2 - 58*x^3 - 32*x^4). - Colin Barker, Feb 27 2018

EXAMPLE

Some solutions for 3 X 4:

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

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

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

CROSSREFS

Cf. A184761.

Sequence in context: A072352 A099100 A208265 * A295244 A264072 A303056

Adjacent sequences: A184753 A184754 A184755 * A184757 A184758 A184759

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 21 2011

STATUS

approved

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Last modified December 2 07:55 EST 2022. Contains 358493 sequences. (Running on oeis4.)