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!)
A252311 Number of (6+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7 1
3681, 3476, 5416, 7489, 14515, 24076, 34279, 70643, 120328, 173799, 386803, 679072, 998407, 2392371, 4310288, 6431079, 16347187, 30013936, 45246631, 119642163, 222278576, 337209639, 912658483, 1706977072, 2598711847, 7123476531 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 6 of A252305
LINKS
FORMULA
Empirical: a(n) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>21
EXAMPLE
Some solutions for n=4
..0..0..0..0..3..0....0..3..0..3..0..0....3..3..1..3..3..1....1..1..1..1..1..1
..0..2..1..0..2..1....0..2..1..3..2..1....3..2..2..3..2..2....1..0..2..1..0..2
..2..3..1..2..3..1....2..0..1..2..0..1....2..3..2..2..3..2....3..1..2..3..1..2
..0..3..0..0..3..0....3..0..0..3..0..0....3..3..0..3..3..0....1..1..1..1..1..1
..0..2..1..0..2..1....3..2..1..3..2..1....3..2..2..3..2..2....1..0..2..1..0..2
..2..3..1..2..0..1....2..0..1..2..3..1....2..3..2..2..3..2....3..1..2..3..1..2
..0..3..0..3..0..0....3..0..0..0..3..0....3..3..0..3..3..1....1..1..1..1..1..1
..0..2..1..3..2..1....3..2..1..0..2..1....3..2..2..3..2..1....1..0..2..1..0..2
CROSSREFS
Sequence in context: A103608 A204757 A250875 * A263814 A179130 A234486
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 16 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 May 23 20:54 EDT 2024. Contains 372765 sequences. (Running on oeis4.)