The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A232510 Number of (n+1)X(3+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal 1
 16, 32, 128, 400, 1344, 4416, 14608, 48224, 159296, 526096, 1737600, 5738880, 18954256, 62601632, 206759168, 682879120, 2255396544, 7449068736, 24602602768, 81256877024, 268373233856, 886376578576, 2927502969600, 9668885487360 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A232515 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 2*a(n-1) +4*a(n-2) +a(n-3). Empirical: G.f.: -16*x / ( (1+x)*(x^2+3*x-1) ), which means a(n) is 16 times 1, 2, 8, 25, 84, 276 and so on with pairs of adjacent numbers summing to A006190. - R. J. Mathar, Nov 23 2014 EXAMPLE Some solutions for n=7 ..0..1..2..1....0..1..0..1....0..1..0..1....0..1..0..1....2..1..0..1 ..0..1..0..1....2..1..2..1....2..1..2..1....2..1..2..1....0..1..2..1 ..2..1..2..1....2..1..2..1....2..1..2..1....0..1..0..1....2..1..0..1 ..2..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....2..1..2..1 ..2..1..2..1....2..1..2..1....2..1..0..1....2..1..2..1....0..1..2..1 ..0..1..0..1....0..1..0..1....0..1..2..1....0..1..2..1....0..1..0..1 ..2..1..2..1....2..1..0..1....0..1..2..1....0..1..0..1....0..1..2..1 ..0..1..0..1....2..1..2..1....2..1..0..1....0..1..2..1....0..1..0..1 CROSSREFS Sequence in context: A115686 A088112 A272697 * A339356 A282832 A331420 Adjacent sequences: A232507 A232508 A232509 * A232511 A232512 A232513 KEYWORD nonn AUTHOR R. H. Hardin, Nov 25 2013 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.

Last modified July 16 12:01 EDT 2024. Contains 374348 sequences. (Running on oeis4.)