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A207704 Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically 4
6, 36, 102, 289, 1071, 3969, 13230, 44100, 153090, 531441, 1815939, 6205081, 21332924, 73342096, 251550372, 862773129, 2961885201, 10168100569, 34894442176, 119749218304, 411007092416, 1410671672089, 4841491994817 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A207703

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +10*a(n-3) +25*a(n-4) -2*a(n-5) +4*a(n-6) -28*a(n-7) -68*a(n-8) -2*a(n-9) +4*a(n-10) +10*a(n-11) +25*a(n-12) +2*a(n-13) -a(n-16)

EXAMPLE

Some solutions for n=4

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

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

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

CROSSREFS

Sequence in context: A207237 A207070 A207118 * A207495 A207249 A060521

Adjacent sequences:  A207701 A207702 A207703 * A207705 A207706 A207707

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 19 2012

STATUS

approved

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Last modified September 23 15:23 EDT 2021. Contains 347618 sequences. (Running on oeis4.)