A242548 Number of length n+3 0..7 arrays with no four elements in a row with pattern aabb (possibly a=b) and new values 0..7 introduced in 0..7 order

13, 43, 166, 712, 3340, 17004, 93103, 543773, 3362689, 21854355, 148145552, 1039764960, 7504319914, 55361803579, 415379230159, 3156808241415, 24223346602916, 187213792659552, 1454634743756302, 11346966341306231

Offset

1,1

Comments

Column 7 of A242549

Links

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

Formula

Empirical: a(n) = 22*a(n-1) -190*a(n-2) +924*a(n-3) -3465*a(n-4) +10962*a(n-5) -24402*a(n-6) +45828*a(n-7) -74016*a(n-8) +19016*a(n-9) -23090*a(n-10) -159064*a(n-11) +571211*a(n-12) +704098*a(n-13) +1846562*a(n-14) +2774132*a(n-15) +616507*a(n-16) -2599138*a(n-17) -8906720*a(n-18) -16117180*a(n-19) -18096476*a(n-20) -15823920*a(n-21) -10584000*a(n-22) -4233600*a(n-23) -705600*a(n-24)

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....1....1....0....0....1....1....1....1....1....1
..1....2....0....2....0....2....2....2....1....1....1....1....0....2....1....2
..0....2....2....1....0....0....3....3....2....2....2....1....0....3....2....3
..2....1....2....3....2....0....1....2....1....1....3....0....1....4....0....4
..1....2....1....4....1....2....0....1....3....0....3....2....2....1....0....4
..1....3....3....0....2....3....3....1....0....2....2....1....3....0....0....0

Crossrefs

Sequence in context: A242545 A242546 A242547 * A104115 A063650 A220612

Adjacent sequences: A242545 A242546 A242547 * A242549 A242550 A242551

Keyword

nonn

Author

R. H. Hardin, May 17 2014

Status

approved