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A260132 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 01010101 or 01010111. 1
58, 128, 342, 730, 1626, 3928, 8998, 20376, 47424, 109650, 251290, 579658, 1338500, 3080858, 7097716, 16367912, 37715574, 86898450, 200293226, 461601736, 1063705902, 2451421760, 5649587496, 13019565474, 30004282786, 69147284586 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-1) + a(n-2) + 5*a(n-3) + a(n-4) - 3*a(n-5) - 3*a(n-6) for n>7.
Empirical g.f.: 2*x*(29 + 35*x + 78*x^2 - 15*x^3 - 72*x^4 - 46*x^5 + 5*x^6) / (1 - x - x^2 - 5*x^3 - x^4 + 3*x^5 + 3*x^6). - Colin Barker, Dec 28 2018
EXAMPLE
Some solutions for n=4:
..1..0..1..0....0..0..1..1....1..0..1..0....0..1..0..1....1..0..0..0
..0..1..0..0....0..1..0..1....1..1..0..1....0..0..1..0....0..1..0..1
..1..0..1..0....1..0..1..0....1..0..1..0....0..1..0..1....1..0..1..0
..1..1..0..1....0..1..0..1....0..1..0..1....1..0..1..0....0..1..0..1
..1..0..1..0....1..0..1..0....0..0..1..0....1..1..0..1....1..0..0..0
..0..1..0..1....1..1..0..0....0..1..0..1....1..0..1..0....0..1..0..1
CROSSREFS
Column 2 of A260138.
Sequence in context: A044626 A039536 A348569 * A180571 A044309 A044690
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 17 2015
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)