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!)
A230935 T(n,k)=Number of black-square subarrays of (n+2)X(k+2) 0..3 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero 9
2, 2, 2, 8, 6, 8, 8, 16, 16, 8, 42, 48, 102, 48, 42, 42, 146, 232, 232, 146, 42, 208, 438, 1682, 1242, 1682, 438, 208, 208, 1312, 3768, 6896, 6896, 3768, 1312, 208, 1042, 3936, 27106, 37984, 98296, 37984, 27106, 3936, 1042, 1042, 11810, 60824, 208172, 396950 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Table starts
...2....2.....8.......8.......42........42........208..........208
...2....6....16......48......146.......438.......1312.........3936
...8...16...102.....232.....1682......3768......27106........60824
...8...48...232....1242.....6896.....37984.....208172......1142054
..42..146..1682....6896....98296....396950....5528862.....22368688
..42..438..3768...37984...396950...4092246...41991510....431437274
.208.1312.27106..208172..5528862..41991510.1088383766...8279222070
.208.3936.60824.1142054.22368688.431437274.8279222070.159130979900
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 4*a(n-2) +5*a(n-4)
k=2: a(n) = 3*a(n-1) -a(n-2) +3*a(n-3)
k=3: a(n) = 16*a(n-2) +3*a(n-4) -10*a(n-6) +24*a(n-8) -16*a(n-10)
k=4: [order 17]
k=5: [order 44]
k=6: [order 71]
EXAMPLE
Some solutions for n=4 k=4
..x..0..x..0..x..2....x..0..x..2..x..2....x..0..x..2..x..2....x..0..x..0..x..2
..3..x..1..x..3..x....1..x..1..x..3..x....1..x..3..x..3..x....3..x..1..x..3..x
..x..0..x..2..x..2....x..2..x..2..x..0....x..2..x..0..x..2....x..2..x..2..x..0
..3..x..1..x..3..x....3..x..1..x..1..x....1..x..3..x..1..x....1..x..3..x..1..x
..x..0..x..2..x..0....x..0..x..2..x..0....x..2..x..0..x..2....x..2..x..0..x..0
..3..x..3..x..1..x....3..x..1..x..3..x....1..x..1..x..3..x....1..x..3..x..3..x
CROSSREFS
Sequence in context: A085484 A326480 A116585 * A008293 A185811 A011140
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 01 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 May 28 15:12 EDT 2024. Contains 372916 sequences. (Running on oeis4.)