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!)
A280905 Number of 4Xn 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1
0, 124, 22632, 1451655, 65348136, 2571528867, 91647699996, 3072729111454, 98499096530389, 3053023277146528, 92172928166402753, 2724604438231223343, 79153860087200853877, 2266446081673358266508, 64102854500808145878543 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A280902.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..87

EXAMPLE

Some solutions for n=3

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

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

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

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

CROSSREFS

Cf. A280902.

Sequence in context: A097842 A206189 A299828 * A146516 A146546 A146553

Adjacent sequences:  A280902 A280903 A280904 * A280906 A280907 A280908

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 10 2017

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 June 29 15:47 EDT 2022. Contains 354913 sequences. (Running on oeis4.)