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

%I #8 Jan 29 2019 09:27:03

%S 40,624,3816,15040,45600,115920,259504,527616,994680,1764400,2976600,

%T 4814784,7514416,11371920,16754400,24110080,33979464,47007216,

%U 63954760,85713600,113319360,147966544,191024016,244051200,308815000,387307440

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

%H R. H. Hardin, <a href="/A269778/b269778.txt">Table of n, a(n) for n = 1..210</a>

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

%F Conjectures from _Colin Barker_, Jan 29 2019: (Start)

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

%F 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.

%F (End)

%e Some solutions for n=3:

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

%e ..3. .0. .0. .3. .3. .3. .2. .2. .3. .2. .3. .0. .3. .0. .0. .3

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

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

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

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

%Y Row 6 of A269776.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 04 2016

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Last modified April 19 21:09 EDT 2024. Contains 371798 sequences. (Running on oeis4.)