A260064 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00000111.

91, 214, 594, 1214, 2367, 5776, 13366, 28064, 63014, 147105, 325915, 721179, 1649899, 3734463, 8328506, 18806873, 42666206, 95949037, 215937944, 488468336, 1102502639, 2483197081, 5605117964, 12658186788, 28545528326, 64390447013

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + a(n-2) + 6*a(n-3) + 4*a(n-4) - 10*a(n-5) - 13*a(n-6) - 12*a(n-7) - 9*a(n-8) + 7*a(n-9) + 6*a(n-10) + 5*a(n-11).

Empirical g.f.: x*(91 + 123*x + 289*x^2 - 140*x^3 - 1089*x^4 - 1315*x^5 - 1114*x^6 - 322*x^7 + 709*x^8 + 596*x^9 + 349*x^10) / (1 - x - x^2 - 6*x^3 - 4*x^4 + 10*x^5 + 13*x^6 + 12*x^7 + 9*x^8 - 7*x^9 - 6*x^10 - 5*x^11). - Colin Barker, Dec 28 2018

Example

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

Crossrefs

Column 2 of A260070.

Sequence in context: A211443 A305761 A339523 * A207077 A293648 A225909

Adjacent sequences: A260061 A260062 A260063 * A260065 A260066 A260067

Keyword

nonn

Author

R. H. Hardin, Jul 14 2015

Status

approved