login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A250413 Number of length n+1 0..2 arrays with the sum of the minimum of each adjacent pair multiplied by some arrangement of +-1 equal to zero. 1
5, 17, 38, 125, 335, 1061, 3069, 9495, 28221, 86149, 258252, 782393, 2350442, 7090347, 21303611, 64109181, 192553620, 578665211, 1737374865, 5217197093, 15659477401, 47004010481, 141055441813, 423295193635, 1270118805510 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 6*a(n-1) - 3*a(n-2) - 40*a(n-3) + 59*a(n-4) + 68*a(n-5) - 146*a(n-6) - 14*a(n-7) + 91*a(n-8) - 8*a(n-9) - 12*a(n-10).

Empirical g.f.: x*(5 - 13*x - 49*x^2 + 148*x^3 + 84*x^4 - 397*x^5 + 40*x^6 + 257*x^7 - 36*x^8 - 36*x^9) / ((1 - x)*(1 - 2*x)*(1 + 2*x)*(1 - 3*x)*(1 - 2*x - x^2 + x^3)*(1 - 3*x^2 - x^3)). - Colin Barker, Nov 14 2018

EXAMPLE

Some solutions for n=6:

..2....0....1....2....2....2....2....2....0....2....2....0....1....0....2....1

..2....0....2....0....1....1....0....1....1....2....0....0....1....0....0....2

..1....0....1....2....0....0....1....1....2....1....1....1....0....1....2....1

..2....2....1....2....2....0....0....0....2....2....1....1....1....1....1....2

..1....0....2....2....2....0....0....0....0....2....0....1....2....2....0....0

..2....2....2....1....1....1....2....0....1....0....1....0....1....2....1....2

..0....0....2....1....0....1....0....1....2....0....1....0....2....2....1....1

CROSSREFS

Column 2 of A250419.

Sequence in context: A212968 A127744 A122734 * A163686 A147165 A147257

Adjacent sequences:  A250410 A250411 A250412 * A250414 A250415 A250416

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 22 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 3 13:21 EDT 2020. Contains 336198 sequences. (Running on oeis4.)