A261288 Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00010101 or 01010101.

166, 233, 504, 1147, 2586, 6034, 14106, 32496, 75202, 175008, 405940, 940390, 2182098, 5064284, 11745648, 27244774, 63209588, 146635614, 340152614, 789099398, 1830590414, 4246594798, 9851282946, 22853254768, 53015328992

Offset

1,1

Comments

Column 4 of A261292.

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) +6*a(n-3) -a(n-4) +4*a(n-5) +a(n-6) -2*a(n-8) +2*a(n-9) -2*a(n-10) -4*a(n-11) -9*a(n-12) +4*a(n-13) -6*a(n-14) -2*a(n-16) -a(n-19) +3*a(n-20) -3*a(n-21) -a(n-24) for n>28

Example

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

Crossrefs

Cf. A261292.

Sequence in context: A015982 A065210 A261261 * A038007 A020361 A256643

Adjacent sequences: A261285 A261286 A261287 * A261289 A261290 A261291

Keyword

nonn

Author

R. H. Hardin, Aug 14 2015

Status

approved