login
A260288
Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001001.
1
104, 201, 544, 1145, 1524, 3591, 8550, 13055, 24762, 60761, 108910, 183673, 423938, 858369, 1438728, 2990881, 6452304, 11431783, 21757610, 47174513, 89535600, 163551107, 342222086, 684851725, 1254030304, 2502106475, 5132607276
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-2) + 6*a(n-3) + 4*a(n-4) - 5*a(n-5) - 12*a(n-6) + 8*a(n-7) + a(n-8) - 11*a(n-9) + 3*a(n-10) for n>12.
Empirical g.f.: x*(104 + 201*x + 440*x^2 + 320*x^3 - 642*x^4 - 1102*x^5 + 233*x^6 + 40*x^7 - 889*x^8 - 7*x^9 + 56*x^10 + 6*x^11) / (1 - x^2 - 6*x^3 - 4*x^4 + 5*x^5 + 12*x^6 - 8*x^7 - x^8 + 11*x^9 - 3*x^10). - Colin Barker, Dec 29 2018
EXAMPLE
Some solutions for n=4:
..1..1..0..0....1..1..0..0....1..0..0..0....1..0..0..1....0..1..0..0
..0..1..0..0....0..1..0..0....0..1..1..0....0..0..1..1....0..1..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..0..0..0
..0..1..0..0....1..1..0..0....0..0..1..1....0..0..1..1....0..0..0..1
..1..0..0..1....1..0..0..0....0..0..0..1....1..0..0..1....0..0..0..0
CROSSREFS
Column 2 of A260294.
Sequence in context: A168528 A259767 A234261 * A044336 A044717 A235990
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 22 2015
STATUS
approved