A211737 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 seven distinct values for every i,j,k<=n

36, 154, 452, 1256, 3308, 8928, 23756, 65304, 178292, 501008, 1397516, 3995336, 11314444, 32748736, 93706276, 273610144, 788528604, 2316859480, 6710869340, 19807293872, 57580298420, 170509860480, 496972052012, 1475204065416

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..54

Formula

Empirical: a(n) = 5*a(n-1) +21*a(n-2) -138*a(n-3) -126*a(n-4) +1552*a(n-5) -238*a(n-6) -9360*a(n-7) +6365*a(n-8) +33365*a(n-9) -33569*a(n-10) -72650*a(n-11) +90866*a(n-12) +95958*a(n-13) -141830*a(n-14) -73556*a(n-15) +128632*a(n-16) +29944*a(n-17) -64696*a(n-18) -5648*a(n-19) +16256*a(n-20) +384*a(n-21) -1536*a(n-22)

Example

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

Crossrefs

Sequence in context: A117511 A250632 A211728 * A211739 A211748 A211757

Adjacent sequences: A211734 A211735 A211736 * A211738 A211739 A211740

Keyword

nonn

Author

R. H. Hardin Apr 20 2012

Status

approved