A211592 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 three, four, five, six or eight distinct values for every i,j,k<=n.

16, 52, 144, 392, 996, 2560, 6348, 16060, 39704, 100212, 248468, 627968, 1562796, 3957156, 9879416, 25055268, 62710372, 159230800, 399332700, 1014876884, 2549391768, 6483648532, 16310176212, 41504086096, 104539323212, 266149720452

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..35

Formula

Empirical: a(n) = 3*a(n-1) +14*a(n-2) -45*a(n-3) -69*a(n-4) +250*a(n-5) +144*a(n-6) -654*a(n-7) -106*a(n-8) +832*a(n-9) -16*a(n-10) -472*a(n-11) +24*a(n-12) +96*a(n-13).

Example

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

Crossrefs

Sequence in context: A009936 A217736 A211578 * A235653 A354886 A087701

Adjacent sequences: A211589 A211590 A211591 * A211593 A211594 A211595

Keyword

nonn

Author

R. H. Hardin, Apr 16 2012

Status

approved