A243032 Number of length n+3 0..7 arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..7 introduced in 0..7 order

13, 43, 163, 694, 3252, 16552, 90634, 529587, 3276946, 21309360, 144513814, 1014502427, 7321836322, 54000875033, 404962560633, 3075437650802, 23577835176467, 182034764991754, 1412748478467391, 11006345014477438

Offset

1,1

Comments

Column 7 of A243033

Links

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

Formula

Empirical: a(n) = 22*a(n-1) -174*a(n-2) +572*a(n-3) -624*a(n-4) +452*a(n-5) -3128*a(n-6) +1972*a(n-7) +2055*a(n-8) +11822*a(n-9) +5790*a(n-10) +1804*a(n-11) -15511*a(n-12) -20914*a(n-13) -24188*a(n-14) -15968*a(n-15) -9299*a(n-16) -3002*a(n-17) -840*a(n-18)

Example

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

Crossrefs

Sequence in context: A243029 A243030 A243031 * A269236 A242545 A242546

Adjacent sequences: A243029 A243030 A243031 * A243033 A243034 A243035

Keyword

nonn

Author

R. H. Hardin, May 29 2014

Status

approved