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!)
A229427 Number of nX7 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing 1
30, 282, 2187, 13345, 66503, 281016, 1037193, 3420692, 10260128, 28379127, 73192023, 177601008, 408454945, 895812869, 1883191437, 3811219431, 7453126082, 14128822736, 26035706883, 46749593643, 81969420795, 140605855270 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 7 of A229428
LINKS
FORMULA
Empirical: a(n) = (1/660441600)*n^14 + (1/9434880)*n^13 + (1/311850)*n^12 + (283/4989600)*n^11 + (23/34560)*n^10 + (5/896)*n^9 + (55843/1587600)*n^8 + (154153/907200)*n^7 + (4503127/7257600)*n^6 + (1244953/725760)*n^5 + (56059/14400)*n^4 + (1646347/302400)*n^3 + (401116003/50450400)*n^2 + (124079/24024)*n + 5
EXAMPLE
Some solutions for n=4
..1..1..0..0..0..0..0....1..1..1..1..0..0..0....1..1..0..0..0..0..0
..1..1..0..0..0..0..0....2..1..1..1..0..0..0....1..1..1..1..0..0..0
..1..1..0..0..0..0..0....2..2..2..1..1..0..0....2..2..1..1..1..1..1
..1..1..0..0..0..0..0....2..2..2..1..1..0..0....2..2..2..2..2..2..1
CROSSREFS
Sequence in context: A214944 A259455 A270852 * A113754 A129029 A101381
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 22 2013
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 April 21 17:36 EDT 2024. Contains 371874 sequences. (Running on oeis4.)