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A269585 Number of length-5 0..n arrays with no repeated value differing from the previous repeated value by more than one. 1

%I #7 Jan 24 2019 11:44:26

%S 32,229,964,2969,7456,16237,31844,57649,97984,158261,245092,366409,

%T 531584,751549,1038916,1408097,1875424,2459269,3180164,4060921,

%U 5126752,6405389,7927204,9725329,11835776,14297557,17152804,20446889,24228544

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

%H R. H. Hardin, <a href="/A269585/b269585.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = n^5 + 5*n^4 + 7*n^3 + 12*n^2 + 6*n + 1.

%F Conjectures from _Colin Barker_, Jan 24 2019: (Start)

%F G.f.: x*(32 + 37*x + 70*x^2 - 20*x^3 + 2*x^4 - x^5) / (1 - x)^6.

%F a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6).

%F (End)

%e Some solutions for n=6:

%e ..5. .4. .1. .6. .2. .4. .0. .4. .6. .6. .3. .6. .2. .1. .1. .0

%e ..3. .2. .5. .6. .1. .0. .6. .5. .5. .2. .4. .3. .6. .1. .4. .4

%e ..5. .4. .4. .0. .5. .1. .5. .1. .4. .4. .0. .2. .6. .2. .3. .6

%e ..2. .2. .2. .2. .4. .2. .6. .6. .4. .5. .3. .1. .1. .2. .6. .5

%e ..2. .0. .6. .0. .4. .4. .4. .1. .2. .6. .3. .0. .2. .6. .0. .4

%Y Row 5 of A269583.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 01 2016

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Last modified April 16 08:27 EDT 2024. Contains 371698 sequences. (Running on oeis4.)