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!)
A252689 Number of (n+2) X (2+2) 0..3 arrays with every consecutive three elements in every row and column having exactly two distinct values, and in every diagonal and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order. 1
96, 142, 204, 519, 1047, 2719, 6483, 16887, 42825, 111655, 288975, 754413, 1965903, 5137567, 13421949, 35100447, 91797087, 240169717, 628416399, 1644575439, 4304194509, 11265951439, 29489332431, 77193738645, 202074840159 (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) = 5*a(n-1) - 4*a(n-2) - 11*a(n-3) + 9*a(n-4) + 12*a(n-5) + 12*a(n-6) - 34*a(n-7) - 8*a(n-8) + 28*a(n-9) - 8*a(n-10) for n>11.

Empirical g.f.: x*(96 - 338*x - 122*x^2 + 1123*x^3 - 34*x^4 - 626*x^5 - 1907*x^6 + 1306*x^7+ 1728*x^8 - 1488*x^9 + 288*x^10) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 3*x + x^2)*(1 - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Dec 05 2018

EXAMPLE

Some solutions for n=4:

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

..0..2..0..2....2..3..3..0....2..3..3..2....2..3..2..3....0..2..2..3

..1..2..1..2....2..1..1..2....0..1..1..2....2..3..2..3....3..1..1..3

..1..0..1..0....0..3..3..0....0..3..3..0....0..1..0..1....0..2..2..0

..3..0..3..0....0..1..1..2....2..1..1..2....0..1..0..1....3..1..1..3

..3..1..3..1....2..3..3..2....2..3..3..2....2..3..2..3....3..2..2..0

CROSSREFS

Column 2 of A252695.

Sequence in context: A323629 A146992 A261287 * A253392 A116119 A039600

Adjacent sequences:  A252686 A252687 A252688 * A252690 A252691 A252692

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 20 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 October 5 12:19 EDT 2022. Contains 357255 sequences. (Running on oeis4.)