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!)
A197556 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,0,2,2 for x=0,1,2,3,4 1
2, 10, 35, 106, 410, 1479, 5280, 18882, 67751, 242440, 867925, 3107159, 11124592, 39826674, 142586969, 510485048, 1827627898, 6543219347, 23425871440, 83868676944, 300264436266, 1074998739399, 3848682051842, 13778949324677 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Every 0 is next to 0 4's, every 1 is next to 1 3's, every 2 is next to 2 0's, every 3 is next to 3 2's, every 4 is next to 4 2's

Column 3 of A197561

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 2*a(n-1) +6*a(n-2) +a(n-3) -4*a(n-4) -17*a(n-5) -4*a(n-6) +35*a(n-7) +49*a(n-8) +24*a(n-9) -14*a(n-10) -44*a(n-11) -40*a(n-12) -20*a(n-13) +4*a(n-14) +9*a(n-15) +2*a(n-16)

EXAMPLE

Some solutions for n=4

..2..0..0....0..2..0....0..0..0....0..2..0....2..0..0....0..2..0....0..0..0

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

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

..2..0..0....0..2..0....0..0..0....0..0..0....2..0..2....0..0..2....0..0..2

CROSSREFS

Sequence in context: A116898 A033261 A236377 * A295133 A100230 A220255

Adjacent sequences:  A197553 A197554 A197555 * A197557 A197558 A197559

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 16 2011

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 August 12 00:34 EDT 2022. Contains 356067 sequences. (Running on oeis4.)