A261287 Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00010101 or 01010101.

96, 133, 271, 504, 1086, 2104, 4715, 9080, 20093, 38864, 86229, 166296, 368773, 712284, 1579561, 3049076, 6762309, 13056148, 28953755, 55898492, 123967937, 239336000, 530772749, 1024728804, 2272547259, 4387441960, 9730031919

Offset

1,1

Comments

Column 3 of A261292.

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +9*a(n-4) +4*a(n-6) -4*a(n-8) +6*a(n-10) -8*a(n-12) -a(n-16) +3*a(n-18) +4*a(n-20) -4*a(n-22) for n>26

Example

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

Crossrefs

Cf. A261292.

Sequence in context: A258748 A323629 A146992 * A252689 A253392 A116119

Adjacent sequences: A261284 A261285 A261286 * A261288 A261289 A261290

Keyword

nonn

Author

R. H. Hardin, Aug 14 2015

Status

approved