A260537 Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00010001.

40, 75, 193, 337, 582, 1350, 2732, 5037, 10549, 21615, 41842, 84846, 172576, 341567, 686447, 1387291, 2770696, 5557618, 11190652, 22426331, 44981821, 90410789, 181399432, 363944476, 730917000, 1467035943, 2944001797, 5910524039

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + a(n-2) + 5*a(n-3) - 2*a(n-4) - 5*a(n-5) - 6*a(n-6) - a(n-7) + 2*a(n-8) + 2*a(n-9) for n>10.

Empirical g.f.: x*(40 + 35*x + 78*x^2 - 131*x^3 - 243*x^4 - 184*x^5 + 116*x^6 + 174*x^7 + 32*x^8 - 36*x^9) / (1 - x - x^2 - 5*x^3 + 2*x^4 + 5*x^5 + 6*x^6 + x^7 - 2*x^8 - 2*x^9). - Colin Barker, Dec 29 2018

Example

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

Crossrefs

Column 1 of A260544.

Sequence in context: A260177 A260170 A260544 * A044106 A044487 A253692

Adjacent sequences: A260534 A260535 A260536 * A260538 A260539 A260540

Keyword

nonn

Author

R. H. Hardin, Jul 28 2015

Status

approved