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A207070 Number of 3Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically 2
6, 36, 102, 288, 896, 2499, 6634, 17848, 47192, 122200, 315315, 809784, 2063670, 5238225, 13261490, 33465000, 84237826, 211676500, 531027000, 1330245423, 3328592562, 8320844952, 20782671568, 51871277456, 129387019195, 322571437760 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A207068

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -9*a(n-2) +21*a(n-3) -56*a(n-4) +64*a(n-5) -89*a(n-6) +192*a(n-7) -119*a(n-8) +117*a(n-9) -305*a(n-10) +46*a(n-11) -64*a(n-12) +323*a(n-13) +39*a(n-14) +36*a(n-15) -228*a(n-16) -56*a(n-17) -4*a(n-18) +80*a(n-19) +24*a(n-20) -16*a(n-22)

EXAMPLE

Some solutions for n=4

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

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

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

CROSSREFS

Sequence in context: A207961 A207243 A207237 * A207118 A207704 A207495

Adjacent sequences:  A207067 A207068 A207069 * A207071 A207072 A207073

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 14 2012

STATUS

approved

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Last modified October 27 10:23 EDT 2021. Contains 348274 sequences. (Running on oeis4.)