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A260974 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00001001 or 00100101 1
91, 133, 239, 481, 925, 1873, 3683, 7321, 14439, 28529, 56363, 111523, 220633, 436539, 863261, 1707243, 3376067, 6677245, 13206405, 26120525, 51660959, 102173689, 202075167, 399659881, 790442205, 1563330291, 3091935925 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A260980

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-2) +2*a(n-3) +a(n-4) +2*a(n-5) +6*a(n-6) +5*a(n-7) -3*a(n-8) -9*a(n-9) -8*a(n-10) -5*a(n-11) for n>14

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Cf. A260980

Sequence in context: A179338 A020238 A220171 * A020301 A083517 A088983

Adjacent sequences:  A260971 A260972 A260973 * A260975 A260976 A260977

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 06 2015

STATUS

approved

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Last modified September 27 20:35 EDT 2020. Contains 337388 sequences. (Running on oeis4.)