A211748 Number of -3..3 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 four, six or eight distinct values for every i,j,k<=n

36, 154, 572, 1960, 6496, 21240, 68636, 224172, 727080, 2404096, 7887572, 26445052, 87756784, 297663312, 996763100, 3410561676, 11496724776, 39585824560, 134072951828, 463716713452, 1575831918928, 5467770323712, 18625362960764

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..55

Formula

Empirical: a(n) = 8*a(n-1) -152*a(n-3) +314*a(n-4) +746*a(n-5) -2694*a(n-6) -604*a(n-7) +8855*a(n-8) -4282*a(n-9) -12546*a(n-10) +11148*a(n-11) +5400*a(n-12) -7920*a(n-13) +1728*a(n-14)

Example

Some solutions for n=5
..0....2...-3....1...-2...-2....3....1....2....0...-2....2...-3....2....3....2
..2....1....2....3...-3....1...-1....3...-1...-2...-1....0....0....0....1....1
..0....2...-1....0....2....0...-2....1....2...-3....2....2....3....2...-2....0
..3...-3....0....1...-3...-1....3....2....1....0....3....0...-2....0....3...-3
..1...-2...-1....0...-2...-2...-2....3...-2...-3....2....3...-3....2....1....2
..2....1....0....1....1....3....3....1...-1...-2...-3....1...-2....0...-2....1

Crossrefs

Sequence in context: A211728 A211737 A211739 * A211757 A250633 A211759

Adjacent sequences: A211745 A211746 A211747 * A211749 A211750 A211751

Keyword

nonn

Author

R. H. Hardin Apr 20 2012

Status

approved