A269676 Number of length-n 0..6 arrays with no repeated value differing from the previous repeated value by other than plus or minus one modulo 6+1.

7, 49, 336, 2282, 15358, 102606, 681254, 4499278, 29579382, 193688894, 1263866086, 8221560942, 53335049558, 345145632286, 2228595939654, 14361269047118, 92377858496182, 593235919318014, 3803941311320486, 24358026991712302

Offset

1,1

Links

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

Formula

Empirical: a(n) = 11*a(n-1) - 22*a(n-2) - 48*a(n-3).

Empirical g.f.: 7*x*(1 - 4*x - 7*x^2) / ((1 - 6*x)*(1 - 5*x - 8*x^2)). - Colin Barker, Jan 26 2019

Example

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

Crossrefs

Column 6 of A269678.

Sequence in context: A268942 A269638 A269535 * A269407 A269604 A269465

Adjacent sequences: A269673 A269674 A269675 * A269677 A269678 A269679

Keyword

nonn

Author

R. H. Hardin, Mar 03 2016

Status

approved