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!)
A233684 Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having the sum of the squares of the edge differences equal to 10, and no two adjacent values equal. 1
32, 108, 356, 1188, 3940, 13108, 43540, 144740, 480964, 1598548, 5312436, 17655684, 58676452, 195006452, 648083796, 2153846948, 7158099972, 23789267092, 79061340148, 262752815812, 873233798180, 2902108995124, 9644881349524 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) + 5*a(n-2) - 2*a(n-3).

Empirical g.f.: 4*x*(8 + 11*x - 5*x^2) / (1 - 2*x - 5*x^2 + 2*x^3). - Colin Barker, Oct 11 2018

EXAMPLE

Some solutions for n=5:

..0..2....2..0....3..1....3..1....2..3....1..0....2..3....1..2....2..1....3..2

..2..1....3..2....2..0....2..3....3..1....3..1....0..2....2..0....0..2....2..0

..0..2....2..0....1..2....0..1....2..0....2..0....2..3....3..1....1..3....0..1

..2..3....3..2....3..1....2..3....1..2....3..2....0..1....1..0....3..2....2..0

..0..2....2..0....2..3....3..1....2..0....1..3....2..3....0..2....2..0....0..1

..1..0....1..2....3..1....2..3....0..1....3..2....0..1....1..3....1..2....2..0

CROSSREFS

Column 1 of A233691.

Sequence in context: A173951 A233691 A337786 * A218068 A333582 A039464

Adjacent sequences:  A233681 A233682 A233683 * A233685 A233686 A233687

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 14 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 22 05:19 EST 2022. Contains 350481 sequences. (Running on oeis4.)