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!)
A199127 Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and no element equal to any horizontal or vertical neighbor 2
1, 2, 2, 12, 30, 30, 210, 560, 560, 4200, 11550, 11550, 90090, 252252, 252252, 2018016, 5717712, 5717712, 46558512, 133024320, 133024320, 1097450640, 3155170590, 3155170590, 26293088250, 75957810500, 75957810500, 638045608200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A199133

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..198

FORMULA

Conjecture: a(3n+2) = a(3n+3) = A208881(n+1). - R. J. Mathar, Nov 01 2015

Conjecture: -(458*n-1205) *(n+2) *(n+1)*a(n) +(-208*n^3+2578*n^2-4613*n-2410) *a(n-1) +9*(-339*n-638) *a(n-2) +27*(n-2) *(458*n^2-289*n-1146) *a(n-3) +54*(n-2) *(n-3) *(104*n-1081) *a(n-4)=0. - R. J. Mathar, Nov 01 2015

Conjecture: (n+2)*(n+1)*a(n) +(5*n^2-2)*a(n-1) +3*(5*n^2-15*n+3) *a(n-2) +3*(n^2 -60*n +81)*a(n-3) +135*(-n^2+3*n-1)*a(n-4) -405*(n-2)*(n-4) *a(n-5) -810*(n-4) *(

n-5) *a(n-6)=0. - R. J. Mathar, Nov 01 2015

EXAMPLE

Some solutions for n=5

..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1

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

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

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

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

CROSSREFS

Sequence in context: A287629 A324919 A130306 * A093044 A151366 A184944

Adjacent sequences:  A199124 A199125 A199126 * A199128 A199129 A199130

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 03 2011

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 February 26 02:19 EST 2020. Contains 332270 sequences. (Running on oeis4.)