STATUS
editing
approved
The OEIS is supported by the many generous donors to the OEIS Foundation.
editing
approved
Empirical: a(n) = 4*a(n-1) +a(n-2) -4*a(n-3) -5*a(n-4) -2*a(n-5) +a(n-6) +2*a(n-7).
Empirical: G.f.: -4*x*(4-3*x-6*x^2-x^3+x^4+x^6) / ( -1+4*x+x^2-4*x^3-5*x^4-2*x^5+x^6+2*x^7 ). - R. J. Mathar, Nov 23 2014
approved
editing
editing
approved
R. H. Hardin, <a href="/A232509/b232509.txt">Table of n, a(n) for n = 1..210</a>
allocated for R. H. Hardin
Number of (n+1)X(2+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
16, 52, 200, 784, 3052, 11900, 46432, 181184, 707044, 2759212, 10767816, 42021520, 163989692, 639972924, 2497507216, 9746573088, 38036202612, 148437067820, 579278732344, 2260647259184, 8822222791628, 34428907339516, 134359524664384
1,1
Column 2 of A232515
Empirical: a(n) = 4*a(n-1) +a(n-2) -4*a(n-3) -5*a(n-4) -2*a(n-5) +a(n-6) +2*a(n-7)
Some solutions for n=7
..2..1..2....0..1..2....2..1..0....0..1..0....0..1..0....2..1..2....2..1..2
..2..1..0....2..1..0....2..1..0....2..1..0....2..1..2....0..1..2....0..1..0
..2..1..0....0..1..2....0..1..0....0..1..2....2..1..0....0..1..0....0..1..2
..2..1..0....0..1..2....2..1..0....2..1..0....2..1..0....2..1..0....0..1..0
..0..1..0....2..1..2....2..1..0....0..1..0....2..1..2....0..1..2....0..1..2
..0..1..2....2..1..0....0..1..0....2..1..0....2..1..2....0..1..2....2..1..0
..0..1..0....0..1..2....0..1..2....2..1..0....2..1..0....2..1..2....2..1..0
..0..1..2....2..1..2....0..1..2....2..1..2....2..1..0....0..1..2....2..1..2
allocated
nonn
R. H. Hardin, Nov 25 2013
approved
editing
allocated for R. H. Hardin
allocated
approved