A211588 - OEIS

%I #4 Apr 16 2012 07:01:32

%S 24,76,216,576,1500,3904,10088,26400,68820,181908,479096,1277104,

%T 3391756,9096984,24311652,65489936,175839276,475150300,1280285828,

%U 3467562340,9368917060,25419679120,68829300080,187003149328,507225916896

%N Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, four, six or eight distinct values for every i,j,k<=n

%H R. H. Hardin, <a href="/A211588/b211588.txt">Table of n, a(n) for n = 1..59</a>

%F Empirical: a(n) = 6*a(n-1) -60*a(n-3) +79*a(n-4) +173*a(n-5) -334*a(n-6) -186*a(n-7) +504*a(n-8) +76*a(n-9) -296*a(n-10) -24*a(n-11) +48*a(n-12)

%e Some solutions for n=5

%e .-1...-1...-2...-1....2...-1...-2...-1...-1...-2....2....0...-2....1....1....0

%e .-2....0...-1....2....0....2...-1....0....0...-1...-2....1....0...-1....1....2

%e .-2...-1...-1....1....1....1...-1....1....1...-2...-2....0...-1...-1....1....2

%e .-1...-2...-1...-2....0....1...-1....0....2...-2....2...-1...-1...-1....1....2

%e .-2...-2...-2....1....1....1...-2...-1...-1....0....2...-2...-1...-1....2....2

%e .-2....0....1...-2....1....2....0....0....0...-1...-2....1...-2....1....2....1

%K nonn

%O 1,1

%A _R. H. Hardin_ Apr 16 2012