A269773 Number of length-n 0..5 arrays with every repeated value unequal to the previous repeated value plus one mod 5+1.

6, 36, 216, 1290, 7680, 45600, 270150, 1597500, 9432000, 55616250, 327585000, 1927725000, 11335143750, 66607312500, 391177125000, 2296246406250, 13473738750000, 79033031250000, 463449377343750, 2716989679687500

Offset

1,1

Links

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

Formula

Empirical: a(n) = 10*a(n-1) - 20*a(n-2) - 25*a(n-3).

Empirical g.f.: 6*x*(1 - 4*x - 4*x^2) / ((1 - 5*x)*(1 - 5*x - 5*x^2)). - Colin Barker, Jan 29 2019

Example

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

Crossrefs

Column 5 of A269776.

Sequence in context: A269432 A269687 A269491 * A269653 A250358 A126634

Adjacent sequences: A269770 A269771 A269772 * A269774 A269775 A269776

Keyword

nonn

Author

R. H. Hardin, Mar 04 2016

Status

approved