A243043 Number of length n+3 0..7 arrays with no four elements in a row with pattern abab (with a!=b) and new values 0..7 introduced in 0..7 order

14, 47, 179, 760, 3545, 17955, 97849, 569236, 3508656, 22742717, 153854313, 1078282250, 7775488348, 57340807380, 430253623025, 3271242719566, 25119643436006, 194328481547041, 1511662452338046, 11807232538631331

Offset

1,1

Comments

Column 7 of A243044

Links

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

Formula

Empirical: a(n) = 23*a(n-1) -190*a(n-2) +614*a(n-3) -135*a(n-4) -2559*a(n-5) +369*a(n-6) +7121*a(n-7) +5143*a(n-8) -7257*a(n-9) -15107*a(n-10) -9219*a(n-11) +2219*a(n-12) +7955*a(n-13) +6635*a(n-14) +3195*a(n-15) +982*a(n-16) +190*a(n-17) +21*a(n-18) +a(n-19)

Example

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

Crossrefs

Sequence in context: A243040 A243041 A243042 * A013323 A205475 A205753

Adjacent sequences: A243040 A243041 A243042 * A243044 A243045 A243046

Keyword

nonn

Author

R. H. Hardin, May 29 2014

Status

approved