A211588 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

24, 76, 216, 576, 1500, 3904, 10088, 26400, 68820, 181908, 479096, 1277104, 3391756, 9096984, 24311652, 65489936, 175839276, 475150300, 1280285828, 3467562340, 9368917060, 25419679120, 68829300080, 187003149328, 507225916896

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..59

Formula

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)

Example

Some solutions for n=5
.-1...-1...-2...-1....2...-1...-2...-1...-1...-2....2....0...-2....1....1....0
.-2....0...-1....2....0....2...-1....0....0...-1...-2....1....0...-1....1....2
.-2...-1...-1....1....1....1...-1....1....1...-2...-2....0...-1...-1....1....2
.-1...-2...-1...-2....0....1...-1....0....2...-2....2...-1...-1...-1....1....2
.-2...-2...-2....1....1....1...-2...-1...-1....0....2...-2...-1...-1....2....2
.-2....0....1...-2....1....2....0....0....0...-1...-2....1...-2....1....2....1

Crossrefs

Sequence in context: A195027 A325958 A211574 * A211596 A214397 A048352

Adjacent sequences: A211585 A211586 A211587 * A211589 A211590 A211591

Keyword

nonn

Author

R. H. Hardin Apr 16 2012

Status

approved