A260974 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00001001 or 00100101

91, 133, 239, 481, 925, 1873, 3683, 7321, 14439, 28529, 56363, 111523, 220633, 436539, 863261, 1707243, 3376067, 6677245, 13206405, 26120525, 51660959, 102173689, 202075167, 399659881, 790442205, 1563330291, 3091935925

Offset

1,1

Comments

Column 2 of A260980

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +2*a(n-3) +a(n-4) +2*a(n-5) +6*a(n-6) +5*a(n-7) -3*a(n-8) -9*a(n-9) -8*a(n-10) -5*a(n-11) for n>14

Example

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

Crossrefs

Cf. A260980

Sequence in context: A020238 A220171 A353062 * A020301 A083517 A088983

Adjacent sequences: A260971 A260972 A260973 * A260975 A260976 A260977

Keyword

nonn

Author

R. H. Hardin, Aug 06 2015

Status

approved