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A207271 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 1 and 1 0 1 vertically 1
9, 81, 193, 611, 1602, 3513, 8327, 17568, 36988, 76723, 153865, 308777, 608391, 1189918, 2313136, 4458599, 8562580, 16354499, 31118601, 59018399, 111556847, 210352934, 395641010, 742567333, 1391072247, 2601239676, 4856734666 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A207269

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +5*a(n-2) -a(n-3) -30*a(n-4) -13*a(n-5) +54*a(n-6) +109*a(n-7) -36*a(n-8) -191*a(n-9) -186*a(n-10) +146*a(n-11) +313*a(n-12) +245*a(n-13) -177*a(n-14) -350*a(n-15) -329*a(n-16) +108*a(n-17) +320*a(n-18) +341*a(n-19) -41*a(n-20) -205*a(n-21) -228*a(n-22) -5*a(n-23) +70*a(n-24) +106*a(n-25) +23*a(n-26) -9*a(n-27) -38*a(n-28) -12*a(n-29) +9*a(n-31) +2*a(n-32) -a(n-34)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A207731 A208690 A207342 * A207764 A207662 A207484

Adjacent sequences:  A207268 A207269 A207270 * A207272 A207273 A207274

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 16 2012

STATUS

approved

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Last modified September 27 15:28 EDT 2021. Contains 347691 sequences. (Running on oeis4.)