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A259717
Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 or 00000011.
1
54, 95, 228, 392, 556, 1219, 2330, 3544, 6772, 13549, 22196, 39298, 77918, 136015, 234216, 449446, 817220, 1411079, 2618246, 4847534, 8502364, 15413237, 28586848, 50995616, 91420870, 168451387, 304255892, 544300220, 994495588, 1808110199
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-2) + 5*a(n-3) + 4*a(n-4) - 4*a(n-5) - 8*a(n-6) - 5*a(n-7) - 3*a(n-8) + 2*a(n-9) + 3*a(n-10).
Empirical g.f.: x*(54 + 95*x + 174*x^2 + 27*x^3 - 363*x^4 - 477*x^5 - 286*x^6 - 81*x^7 + 152*x^8 + 156*x^9) / (1 - x^2 - 5*x^3 - 4*x^4 + 4*x^5 + 8*x^6 + 5*x^7 + 3*x^8 - 2*x^9 - 3*x^10). - Colin Barker, Dec 26 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..0....0..1..0..0....1..0..0..0....1..0..0..0....1..1..0..0
..0..1..0..0....0..0..0..0....1..0..0..0....1..0..0..1....0..1..0..0
..0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..1..0....0..0..0..1....0..0..0..0....0..0..0..0
..1..1..0..0....0..0..1..0....1..0..0..0....1..1..0..0....0..0..1..0
..0..0..0..0....0..0..0..0....1..0..0..0....0..0..0..0....0..0..0..1
CROSSREFS
Column 2 of A259723.
Sequence in context: A071863 A045933 A088986 * A118150 A039779 A044143
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 03 2015
STATUS
approved