A260011 Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000101 00010101 or 01010101

209, 578, 2492, 8450, 25600, 84050, 292422, 985608, 3251280, 10857800, 36602762, 122774450, 410260884, 1373718528, 4607045940, 15437704898, 51696499120, 173176718162, 580275938368, 1944096211250, 6512576848570, 21817926896768

Offset

1,1

Comments

Column 4 of A260015

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +9*a(n-3) +27*a(n-4) -13*a(n-5) -a(n-6) -54*a(n-7) -129*a(n-8) +13*a(n-9) -2*a(n-10) +48*a(n-11) +108*a(n-12) -4*a(n-13) -8*a(n-15) -16*a(n-16) for n>17

Example

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

Crossrefs

Cf. A260015

Sequence in context: A250780 A305173 A316761 * A203048 A203041 A293981

Adjacent sequences: A260008 A260009 A260010 * A260012 A260013 A260014

Keyword

nonn

Author

R. H. Hardin, Jul 13 2015

Status

approved