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!)
A200789 Number of 0..n arrays x(0..6) of 7 elements without any two consecutive increases. 1

%I #15 Oct 21 2017 21:51:54

%S 128,1791,11704,50775,169884,474566,1160616,2562633,5217520,9944957,

%T 17946864,30927871,51238812,82045260,127523120,193083297,285627456,

%U 413836891,588496520,822856023,1133030140,1538440146,2062298520

%N Number of 0..n arrays x(0..6) of 7 elements without any two consecutive increases.

%C Row 5 of A200785.

%H R. H. Hardin, <a href="/A200789/b200789.txt">Table of n, a(n) for n = 1..137</a>

%F Empirical: a(n) = (2017/5040)*n^7 + (1427/360)*n^6 + (5759/360)*n^5 + (607/18)*n^4 + (28459/720)*n^3 + (9113/360)*n^2 + (848/105)*n + 1.

%F Conjectures from _Colin Barker_, Oct 15 2017: (Start)

%F The formulas below are consistent with the conjectured formula above.

%F G.f.: x*(128 + 767*x + 960*x^2 + 123*x^3 + 60*x^4 - 28*x^5 + 8*x^6 - x^7) / (1 - x)^8.

%F a(n) = (5040 + 40704*n + 127582*n^2 + 199213*n^3 + 169960*n^4 + 80626*n^5 + 19978*n^6 + 2017*n^7) / 5040.

%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=3

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

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 22 2011

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 24 13:58 EDT 2024. Contains 371960 sequences. (Running on oeis4.)