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!)
A232516 Number of (1+1) X (n+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal. 1
4, 16, 16, 54, 74, 218, 340, 868, 1494, 3528, 6466, 14494, 27650, 59992, 117432, 249546, 496576, 1041354, 2094122, 4354594, 8815964, 18233764, 37073438, 76414688, 155795194, 320416958, 654414674, 1344022320, 2748080744, 5638905938 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 1 of A232515.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-2) +a(n-3) +2*a(n-4) +2*a(n-5).
Empirical: G.f.: -2*x*(2+8*x+2*x^2+x^3+x^4) / ( -1+3*x^2+x^3+2*x^4+2*x^5 ). - R. J. Mathar, Nov 23 2014
EXAMPLE
Some solutions for n=7
..2..1..2..1..0..2..1..0....1..0..1..2..1..0..1..2....1..2..1..2..1..0..1..0
..2..1..0..1..0..2..1..2....1..2..1..2..1..0..1..2....1..0..1..2..1..2..1..0
CROSSREFS
Cf. A232515.
Sequence in context: A223876 A223801 A336938 * A220109 A207283 A207479
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 25 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 July 19 05:20 EDT 2024. Contains 374388 sequences. (Running on oeis4.)