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!)
A209101 Number of 2Xn 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors 1
2, 11, 76, 520, 3552, 24256, 165632, 1131008, 7723008, 52736000, 360103936, 2458943488, 16790716416, 114654183424, 782907736064, 5346028421120, 36504965480448, 249271496474624, 1702132247953408, 11622886011830272 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 2 of A209100

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) -8*a(n-2) for n>3

EXAMPLE

Some solutions for n=4

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

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

CROSSREFS

Sequence in context: A220878 A049363 A055085 * A118802 A053481 A110329

Adjacent sequences:  A209098 A209099 A209100 * A209102 A209103 A209104

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 05 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 10 15:13 EST 2016. Contains 279003 sequences.