A261375 Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101.

60, 82, 202, 424, 869, 1714, 3778, 7462, 15888, 31618, 68245, 135058, 290195, 575938, 1238957, 2455954, 5282429, 10475722, 22530337, 44674906, 96090169, 190539730, 409810129, 812624530, 1747814377, 3465775738, 7454228289, 14781184618

Offset

1,1

Comments

Column 3 of A261380.

Links

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

Formula

Empirical: a(n) = a(n-2) +11*a(n-4) +13*a(n-6) -2*a(n-8) -2*a(n-10) +4*a(n-12) for n>17

Example

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

Crossrefs

Cf. A261380.

Sequence in context: A290018 A323979 A067207 * A349758 A217740 A123712

Adjacent sequences: A261372 A261373 A261374 * A261376 A261377 A261378

Keyword

nonn

Author

R. H. Hardin, Aug 17 2015

Status

approved