A269492 Number of length-n 0..6 arrays with no repeated value differing from the previous repeated value by one.

7, 49, 343, 2389, 16579, 114695, 791381, 5448185, 37435583, 256804141, 1759152499, 12035747757, 82258781115, 561684075373, 3832259642203, 26128574285113, 178038236615119, 1212498463318805, 8253697161562331, 56161736795827953

Offset

1,1

Links

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

Formula

Empirical: a(n) = 30*a(n-1) - 353*a(n-2) + 1992*a(n-3) - 4976*a(n-4) + 1872*a(n-5) + 8202*a(n-6) + 1800*a(n-7) - 210*a(n-8) - 36*a(n-9).

Empirical g.f.: x*(7 - 161*x + 1344*x^2 - 4548*x^3 + 3212*x^4 + 8106*x^5 + 1656*x^6 - 208*x^7 - 34*x^8) / ((1 - 6*x)*(1 - 24*x + 209*x^2 - 738*x^3 + 548*x^4 + 1416*x^5 + 294*x^6 - 36*x^7 - 6*x^8)). - Colin Barker, Jan 23 2019

Example

Some solutions for n=6:
..1. .0. .0. .5. .0. .0. .2. .0. .5. .3. .0. .6. .6. .5. .6. .4
..6. .0. .2. .3. .1. .0. .4. .0. .4. .0. .3. .0. .2. .0. .4. .2
..6. .3. .1. .4. .4. .4. .5. .3. .2. .1. .2. .0. .4. .6. .1. .0
..0. .3. .4. .6. .1. .3. .6. .5. .6. .6. .5. .0. .0. .2. .4. .2
..6. .1. .5. .4. .5. .2. .1. .5. .6. .3. .5. .1. .5. .0. .6. .4
..2. .6. .0. .2. .3. .3. .0. .1. .0. .6. .3. .3. .2. .0. .4. .1

Crossrefs

Column 6 of A269494.

Sequence in context: A269581 A269433 A269688 * A269774 A269654 A250359

Adjacent sequences: A269489 A269490 A269491 * A269493 A269494 A269495

Keyword

nonn

Author

R. H. Hardin, Feb 28 2016

Status

approved