A244694 Number of length n+4 0..2 arrays with no five consecutive elements with pattern ababa or abbba (with a!=b) and new values 0..2 introduced in 0..2 order.

39, 111, 317, 908, 2602, 7459, 21383, 61302, 175745, 503841, 1444456, 4141097, 11872072, 34035934, 97577307, 279743489, 801994051, 2299229415, 6591639797, 18897511895, 54177104154, 155319844796, 445285043640, 1276583622333

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) - a(n-3) - a(n-5) + a(n-6) - a(n-7).

Empirical g.f.: x*(39 - 6*x - 16*x^2 - 4*x^3 - 11*x^4 + 9*x^5 - 14*x^6) / ((1 - x)*(1 + x)*(1 - 3*x + x^2 - 2*x^3 + x^4 - x^5)). - Colin Barker, Nov 03 2018

Example

Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....0....1....1....0....1....0....0....1....0....1....1
..2....0....0....0....1....1....1....2....0....0....0....1....1....1....0....1
..0....2....0....2....0....1....0....2....1....2....1....1....1....1....0....2
..0....1....2....0....1....0....0....2....0....1....0....2....2....1....2....0
..2....2....2....0....2....1....1....0....2....1....0....1....1....2....1....2
..2....2....0....0....1....2....2....0....1....0....1....0....1....2....0....1
..1....2....2....1....2....2....0....0....1....0....2....2....0....1....2....1
..0....0....2....1....2....1....0....0....1....2....2....0....2....1....2....0
..1....1....2....2....1....1....2....2....0....0....0....1....0....2....1....2

Crossrefs

Column 2 of A244702.

Sequence in context: A276401 A044226 A044607 * A008878 A249301 A239562

Adjacent sequences: A244691 A244692 A244693 * A244695 A244696 A244697

Keyword

nonn

Author

R. H. Hardin, Jul 04 2014

Status

approved