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A207897 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 0 and 1 1 1 vertically 1
10, 100, 292, 870, 2446, 6952, 20168, 57838, 164914, 473632, 1360740, 3896086, 11165294, 32038792, 91859552, 263284722, 754983634, 2164966616, 6206791972, 17795617610, 51026354878, 146302277604, 419468202104, 1202710746958 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A207895

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-2) +10*a(n-3) +18*a(n-4) -2*a(n-5) -22*a(n-6) -7*a(n-7) -12*a(n-9) -8*a(n-10) -6*a(n-11) -6*a(n-12) -3*a(n-13) -a(n-14) +3*a(n-15) +a(n-16) -a(n-17) for n>18

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A208684 A207348 A207770 * A207657 A305668 A262761

Adjacent sequences:  A207894 A207895 A207896 * A207898 A207899 A207900

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 21 2012

STATUS

approved

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Last modified December 4 17:03 EST 2021. Contains 349526 sequences. (Running on oeis4.)