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A261374 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101. 1
39, 41, 82, 157, 266, 470, 864, 1553, 2758, 4960, 8924, 16001, 28662, 51503, 92374, 165796, 297284, 533858, 957252, 1718645, 3081790, 5533474, 9922064, 17814980, 31944528, 57356546, 102846820, 184661677, 331120454, 594527399, 1066057422 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A261380.

LINKS

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

FORMULA

Empirical: a(n) = a(n-2) +6*a(n-4) +4*a(n-6) -a(n-8) for n>9

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Cf. A261380.

Sequence in context: A050774 A041759 A257442 * A061756 A236673 A119028

Adjacent sequences:  A261371 A261372 A261373 * A261375 A261376 A261377

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 17 2015

STATUS

approved

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Last modified August 17 23:58 EDT 2017. Contains 290682 sequences.