A259946 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00000101.

60, 170, 549, 1507, 4128, 11933, 34337, 97374, 277073, 791655, 2258776, 6438153, 18360749, 52375446, 149376869, 426006811, 1215002568, 3465304429, 9883190601, 28187259534, 80391677785, 229281523567, 653922541496, 1865020964353

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) + a(n-3) + 6*a(n-4) - 14*a(n-5) - 4*a(n-6) + 2*a(n-7) - 4*a(n-8) + 4*a(n-9) for n>10.

Empirical g.f.: x*(60 + 50*x + 89*x^2 + 9*x^3 - 514*x^4 - 66*x^5 + 34*x^6 - 90*x^7 + 144*x^8 - 12*x^9) / ((1 + x - x^2)*(1 - 3*x + 2*x^2 - 6*x^3 + 2*x^4 + 6*x^5 + 4*x^7)). - Colin Barker, Dec 27 2018

Example

Some solutions for n=4:
..0..1..0..0....0..0..0..0....0..0..1..0....0..0..0..0....1..0..0..0
..1..0..0..0....0..0..0..0....0..0..0..1....1..0..0..0....0..0..0..1
..0..0..0..0....1..0..0..1....0..0..0..0....0..0..0..0....1..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..1
..1..0..0..1....0..0..0..1....0..0..1..0....0..0..0..0....0..0..0..0
..0..0..0..0....1..0..0..0....0..0..0..1....0..0..1..0....1..0..0..1

Crossrefs

Column 2 of A259952.

Sequence in context: A216480 A257146 A291549 * A249911 A292223 A112827

Adjacent sequences: A259943 A259944 A259945 * A259947 A259948 A259949

Keyword

nonn

Author

R. H. Hardin, Jul 10 2015

Status

approved