A243031 Number of length n+3 0..6 arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..6 introduced in 0..6 order

13, 43, 163, 694, 3251, 16516, 89891, 517995, 3124633, 19526936, 125310013, 819900515, 5439853987, 36450654645, 245947876098, 1667610573306, 11345449253135, 77370823036978, 528505154812999, 3614268384433002

Offset

1,1

Comments

Column 6 of A243033

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -84*a(n-2) +150*a(n-3) -60*a(n-4) +328*a(n-5) -613*a(n-6) -360*a(n-7) -1052*a(n-8) +372*a(n-9) +773*a(n-10) +1906*a(n-11) +1441*a(n-12) +1124*a(n-13) +396*a(n-14) +144*a(n-15)

Example

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

Crossrefs

Sequence in context: A303740 A243029 A243030 * A243032 A269236 A242545

Adjacent sequences: A243028 A243029 A243030 * A243032 A243033 A243034

Keyword

nonn

Author

R. H. Hardin, May 29 2014

Status

approved