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!)
A250143 Number of length 4+2 0..n arrays with the medians of every three consecutive terms nondecreasing. 1
41, 391, 1959, 6902, 19446, 46914, 100962, 199023, 365959, 635921, 1054417, 1680588, 2589692, 3875796, 5654676, 8066925, 11281269, 15498091, 20953163, 27921586, 36721938, 47720630, 61336470, 78045435, 98385651, 122962581 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = (13/45)*n^6 + (5/2)*n^5 + (595/72)*n^4 + (53/4)*n^3 + (3941/360)*n^2 + (19/4)*n + 1.
Conjectures from Colin Barker, Nov 11 2018: (Start)
G.f.: x*(41 + 104*x + 83*x^2 - 35*x^3 + 21*x^4 - 7*x^5 + x^6) / (1 - x)^7.
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.
(End)
EXAMPLE
Some solutions for n=6:
6 0 5 2 0 0 0 0 0 2 0 4 1 1 4 3
0 0 2 5 3 4 6 2 0 3 5 6 3 1 0 3
1 4 2 2 0 0 2 3 1 5 4 0 2 6 4 1
6 0 2 1 4 5 2 6 0 5 4 6 2 5 6 3
6 3 6 3 5 5 6 1 6 5 5 6 3 2 6 4
5 6 6 5 4 6 2 5 6 3 1 4 1 6 2 5
CROSSREFS
Row 4 of A250140.
Sequence in context: A196576 A090211 A274725 * A069594 A124338 A008356
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 13 2014
STATUS
approved

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 June 10 13:16 EDT 2023. Contains 363205 sequences. (Running on oeis4.)