A269580 Number of length-n 0..5 arrays with no repeated value differing from the previous repeated value by more than one.

6, 36, 216, 1276, 7456, 43184, 248324, 1419502, 8074172, 45734140, 258127540, 1452448400, 8151217700, 45640705908, 255046211478, 1422758512212, 7924694792032, 44081166810484, 244913122501544, 1359313355233592

Offset

1,1

Links

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

Formula

Empirical: a(n) = 20*a(n-1) - 146*a(n-2) + 440*a(n-3) - 328*a(n-4) - 470*a(n-5) - 76*a(n-6) + 5*a(n-7).

Empirical g.f.: 2*x*(3 - 42*x + 186*x^2 - 214*x^3 - 200*x^4 - 26*x^5 + 2*x^6) / ((1 - 5*x)*(1 - 15*x + 71*x^2 - 85*x^3 - 97*x^4 - 15*x^5 + x^6)). - Colin Barker, Jan 24 2019

Example

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

Crossrefs

Column 5 of A269583.

Sequence in context: A228737 A007274 A269616 * A269432 A269687 A269491

Adjacent sequences: A269577 A269578 A269579 * A269581 A269582 A269583

Keyword

nonn

Author

R. H. Hardin, Mar 01 2016

Status

approved