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!)
A268793 Number of nX3 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once. 1
12, 78, 248, 950, 3384, 11948, 41248, 140698, 474472, 1586038, 5262024, 17348096, 56884272, 185647624, 603388088, 1953997896, 6307338900, 20300666174, 65169102416, 208712267048, 666993883320, 2127375490930, 6773070493400 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A268798.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +9*a(n-2) -2*a(n-3) -33*a(n-4) -42*a(n-5) -14*a(n-6) +10*a(n-7) +8*a(n-8) -a(n-10) for n>12
EXAMPLE
Some solutions for n=4
..2..2..1. .0..1..2. .0..0..0. .1..0..1. .1..0..0. .2..2..2. .2..1..0
..1..2..2. .1..2..2. .1..0..1. .0..1..0. .0..0..1. .2..2..2. .1..0..1
..1..2..1. .2..2..2. .0..1..0. .0..0..1. .0..0..2. .1..2..1. .0..0..0
..2..2..2. .2..2..1. .0..0..0. .1..0..0. .0..1..2. .2..1..0. .0..1..0
CROSSREFS
Cf. A268798.
Sequence in context: A136540 A139612 A304503 * A162629 A008504 A008494
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2016
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 March 28 13:42 EDT 2024. Contains 371254 sequences. (Running on oeis4.)