login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A204295 Number of n X 2 0..3 arrays with every element neighboring horizontally or vertically both a 0 and a 1, and 2 introduced before 3 in row major order. 1
0, 4, 4, 16, 68, 212, 776, 3076, 11540, 44944, 177748, 700292, 2779272, 11069140, 44107780, 176038288, 703199588, 2809956020, 11232774920, 44913243940, 179603461748, 718287355024, 2872823053300, 11490415637348, 45959392743048 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A204301.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +2*a(n-2) +4*a(n-3) -42*a(n-4) -30*a(n-5) +13*a(n-6) +38*a(n-7) +28*a(n-8) -16*a(n-9).

EXAMPLE

Some solutions for n=5:

..0..0....0..1....0..1....1..1....0..0....1..0....0..1....0..1....1..0....0..0

..1..1....0..1....0..1....0..0....1..1....1..0....0..1....0..1....1..0....1..1

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

..1..1....1..0....0..0....1..1....0..0....0..1....1..0....1..0....1..0....0..1

..0..0....1..0....1..1....0..0....1..1....0..1....1..0....1..0....1..0....0..1

CROSSREFS

Cf. A204301.

Sequence in context: A203536 A038788 A010099 * A203101 A060691 A075225

Adjacent sequences:  A204292 A204293 A204294 * A204296 A204297 A204298

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 14 2012

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 5 07:11 EST 2016. Contains 278761 sequences.