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A207786 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically 1
9, 81, 253, 791, 2173, 5241, 12567, 28101, 61397, 131083, 272789, 560651, 1133751, 2266643, 4487109, 8799557, 17130019, 33113221, 63623053, 121586791, 231212705, 437760595, 825496887, 1550995293, 2904417145, 5422206945, 10094193051 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A207785

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) -13*a(n-3) -6*a(n-4) +41*a(n-5) +10*a(n-6) -57*a(n-7) -32*a(n-8) +66*a(n-9) +18*a(n-10) -31*a(n-11) +14*a(n-13) -30*a(n-14) +4*a(n-15) +32*a(n-16) -13*a(n-17) -12*a(n-18) +a(n-19) +6*a(n-20) -9*a(n-21) +12*a(n-22) -2*a(n-23) -3*a(n-25) +2*a(n-26) -2*a(n-27) +a(n-28)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A207415 A207020 A207364 * A223189 A207781 A207165

Adjacent sequences:  A207783 A207784 A207785 * A207787 A207788 A207789

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 20 2012

STATUS

approved

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Last modified July 2 03:47 EDT 2022. Contains 354985 sequences. (Running on oeis4.)