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A261108 Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010001 00010101 or 01010101. 1
63, 106, 278, 566, 1408, 2902, 7284, 14942, 37432, 76838, 192624, 395390, 990928, 2034038, 5098214, 10464850, 26228746, 53838574, 134940686, 276986458, 694234628, 1425023498, 3571661670, 7331384958, 18375286712, 37718103630 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-2) + 10*a(n-4) + 5*a(n-6) + 2*a(n-8) - 2*a(n-10) + a(n-12) for n>13.

Empirical g.f.: x*(63 + 106*x + 89*x^2 + 248*x^3 - 56*x^4 + 144*x^5 - 35*x^6 + 46*x^7 - 16*x^8 - 50*x^9 + 18*x^10 + 26*x^11 - 7*x^12) / (1 - 3*x^2 - 10*x^4 - 5*x^6 - 2*x^8 + 2*x^10 - x^12). - Colin Barker, Dec 30 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 3 of A261113.

Sequence in context: A023688 A118157 A257897 * A147194 A147398 A166394

Adjacent sequences:  A261105 A261106 A261107 * A261109 A261110 A261111

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 08 2015

STATUS

approved

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Last modified June 24 04:38 EDT 2019. Contains 324318 sequences. (Running on oeis4.)