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

%I #8 Jan 29 2019 05:25:03

%S 6,36,216,1290,7680,45600,270150,1597500,9432000,55616250,327585000,

%T 1927725000,11335143750,66607312500,391177125000,2296246406250,

%U 13473738750000,79033031250000,463449377343750,2716989679687500

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

%H R. H. Hardin, <a href="/A269773/b269773.txt">Table of n, a(n) for n = 1..210</a>

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

%F 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

%e Some solutions for n=6:

%e ..0. .2. .2. .1. .4. .1. .4. .0. .4. .2. .0. .3. .4. .3. .5. .4

%e ..4. .2. .3. .5. .4. .1. .2. .5. .1. .0. .1. .0. .0. .5. .4. .3

%e ..5. .4. .0. .4. .3. .0. .5. .4. .1. .3. .1. .0. .2. .3. .5. .4

%e ..3. .4. .5. .4. .3. .4. .1. .5. .0. .1. .2. .1. .3. .5. .5. .2

%e ..1. .2. .1. .0. .2. .1. .5. .3. .1. .3. .3. .3. .0. .1. .3. .2

%e ..4. .3. .2. .1. .3. .0. .0. .3. .4. .4. .3. .2. .2. .1. .4. .1

%Y Column 5 of A269776.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 04 2016