A221458 Number of 0..7 arrays of length n with each element unequal to at least one neighbor, with new values introduced in 0..7 order

0, 1, 2, 7, 25, 102, 456, 2219, 11639, 65320, 389533, 2451393, 16164044, 110866328, 785411383, 5709898562, 42358751505, 319155928942, 2433165471304, 18714220718157, 144885627697659, 1127182676182780, 8800901309557829

Offset

1,3

Comments

Column 7 of A221459

Links

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

Formula

Empirical: a(n) = 22*a(n-1) -168*a(n-2) +440*a(n-3) +421*a(n-4) -2898*a(n-5) -924*a(n-6) +7944*a(n-7) +5931*a(n-8) -6610*a(n-9) -10562*a(n-10) -5040*a(n-11) -840*a(n-12)

Example

Some solutions for n=6
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1
..2....1....1....2....0....2....0....0....2....1....1....0....2....2....0....2
..3....2....0....3....1....2....1....2....0....2....2....0....0....2....0....1
..0....1....0....3....2....1....2....2....3....0....2....2....1....3....2....1
..2....0....2....2....1....0....3....1....4....3....0....0....0....1....1....0

Crossrefs

Sequence in context: A036784 A221456 A221457 * A221453 A097597 A150512

Adjacent sequences: A221455 A221456 A221457 * A221459 A221460 A221461

Keyword

nonn

Author

R. H. Hardin Jan 17 2013

Status

approved