The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A203881 Number of (n+1) X 3 0..6 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements. 1
8281, 254359, 7501753, 222645367, 6601376089, 195759462871, 5804976472057, 172139217677623, 5104567195084441, 151369391916622999, 4488665070837227833, 133105602855424669687, 3947075851161154183129, 117045469473077458995031 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A203887.
LINKS
FORMULA
Empirical: a(n) = 25*a(n-1) +138*a(n-2).
Empirical g.f.: 49*x*(169 + 966*x) / (1 - 25*x - 138*x^2). - Colin Barker, Jun 05 2018
EXAMPLE
Some solutions for n=4:
..0..5..2....4..1..5....4..0..4....1..2..1....2..0..1....0..0..5....4..5..3
..5..0..5....5..4..1....1..4..3....1..1..5....2..2..0....5..0..0....3..4..5
..2..5..6....2..5..4....5..1..4....5..1..1....6..2..2....3..5..0....1..3..4
..3..2..5....5..1..5....6..5..1....3..5..1....3..6..2....1..3..5....1..1..3
..3..3..2....3..5..5....4..6..5....2..3..5....5..3..6....1..1..3....1..6..1
CROSSREFS
Cf. A203887.
Sequence in context: A252581 A271748 A064014 * A145527 A054215 A031589
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2012
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 18 18:14 EDT 2024. Contains 373486 sequences. (Running on oeis4.)