A243387 Number of length n+3 0..6 arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..6 introduced in 0..6 order.

14, 46, 174, 737, 3434, 17366, 94164, 541060, 3257286, 20333069, 130439432, 853756157, 5669606647, 38041540586, 257118895765, 1746784622435, 11909889453316, 81408594286227, 557440239347213, 3821747622458620

Offset

1,1

Comments

Column 6 of A243389.

Links

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

Formula

Empirical: a(n) = 22*a(n-1) -195*a(n-2) +914*a(n-3) -2539*a(n-4) +4594*a(n-5) -6074*a(n-6) +6382*a(n-7) -5368*a(n-8) +3726*a(n-9) -2167*a(n-10) +1026*a(n-11) -419*a(n-12) +130*a(n-13) -36*a(n-14) +6*a(n-15) -a(n-16).

Example

Some solutions for n=3
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....0....1....1....0....1....1....1....0....1....1....1....1....1....1
..0....1....1....2....1....0....0....1....1....0....2....1....2....0....0....2
..2....2....2....3....2....1....2....1....1....0....3....2....3....2....0....1
..1....1....1....4....0....2....3....0....2....0....0....2....2....0....2....2
..0....3....0....1....2....2....2....2....1....1....1....2....0....2....0....3

Crossrefs

Cf. A243389.

Sequence in context: A243385 A242580 A243386 * A243388 A242581 A242582

Adjacent sequences: A243384 A243385 A243386 * A243388 A243389 A243390

Keyword

nonn

Author

R. H. Hardin, Jun 04 2014

Status

approved