The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A269584 Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by more than one. 1

%I #7 Jan 24 2019 11:44:34

%S 16,79,250,613,1276,2371,4054,6505,9928,14551,20626,28429,38260,50443,

%T 65326,83281,104704,130015,159658,194101,233836,279379,331270,390073,

%U 456376,530791,613954,706525,809188,922651,1047646,1184929,1335280

%N Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by more than one.

%H R. H. Hardin, <a href="/A269584/b269584.txt">Table of n, a(n) for n = 1..210</a>

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

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

%F G.f.: x*(16 - x + 15*x^2 - 7*x^3 + x^4) / (1 - x)^5.

%F a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.

%F (End)

%e Some solutions for n=6:

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

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

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

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

%Y Row 4 of A269583.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 01 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 28 17:53 EST 2023. Contains 367419 sequences. (Running on oeis4.)