A269778 Number of length-6 0..n arrays with every repeated value unequal to the previous repeated value plus one mod n+1.

40, 624, 3816, 15040, 45600, 115920, 259504, 527616, 994680, 1764400, 2976600, 4814784, 7514416, 11371920, 16754400, 24110080, 33979464, 47007216, 63954760, 85713600, 113319360, 147966544, 191024016, 244051200, 308815000, 387307440

Offset

1,1

Links

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

Formula

Empirical: a(n) = n^6 + 6*n^5 + 15*n^4 + 14*n^3 + 4*n^2.

Conjectures from Colin Barker, Jan 29 2019: (Start)

G.f.: 8*x*(5 + 43*x + 36*x^2 + 4*x^3 + 2*x^4) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.

(End)

Example

Some solutions for n=3:
..3. .1. .3. .1. .1. .3. .3. .1. .2. .2. .3. .3. .0. .2. .1. .2
..3. .0. .0. .3. .3. .3. .2. .2. .3. .2. .3. .0. .3. .0. .0. .3
..1. .3. .0. .3. .3. .3. .0. .3. .2. .1. .3. .3. .3. .0. .0. .1
..1. .2. .1. .0. .3. .3. .2. .3. .1. .1. .2. .0. .0. .0. .3. .0
..2. .1. .2. .2. .3. .0. .1. .0. .2. .2. .3. .1. .2. .0. .0. .3
..3. .2. .2. .2. .0. .1. .2. .3. .0. .1. .1. .1. .3. .3. .1. .0

Crossrefs

Row 6 of A269776.

Sequence in context: A263953 A002847 A057808 * A229696 A247410 A183464

Adjacent sequences: A269775 A269776 A269777 * A269779 A269780 A269781

Keyword

nonn

Author

R. H. Hardin, Mar 04 2016

Status

approved