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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A254704 Number of length 6+4 0..n arrays with every five consecutive terms having the maximum of some two terms equal to the minimum of the remaining three terms. 1

%I #8 Dec 17 2018 15:24:52

%S 212,4542,37204,183491,665256,1961608,4985336,11325573,23567212,

%T 45697586,83610924,145721095,243693152,393304188,615444016,937266185,

%U 1393499844,2027932966,2895077444,4062026571,5610515416,7639194608,10266128040

%N Number of length 6+4 0..n arrays with every five consecutive terms having the maximum of some two terms equal to the minimum of the remaining three terms.

%H R. H. Hardin, <a href="/A254704/b254704.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (73/35)*n^7 + 19*n^6 + 52*n^5 + 60*n^4 + (377/10)*n^3 + 26*n^2 + (199/14)*n + 1.

%F Conjectures from _Colin Barker_, Dec 17 2018: (Start)

%F G.f.: x*(212 + 2846*x + 6804*x^2 + 1163*x^3 - 472*x^4 - 48*x^5 + 8*x^6 - x^7) / (1 - x)^8.

%F a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.

%F (End)

%e Some solutions for n=4:

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

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

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

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

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

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

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

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

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

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

%Y Row 6 of A254698.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 05 2015

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 09:16 EDT 2024. Contains 371967 sequences. (Running on oeis4.)