A211727 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 one, two, three, four or five distinct values for every i,j,k<=n

49, 131, 311, 719, 1627, 3679, 8283, 18713, 42325, 96169, 219263, 502397, 1156113, 2673435, 6209225, 14485465, 33927541, 79766671, 188169795, 445268391, 1056497233, 2512864191, 5989377967, 14302062153, 34206279091, 81924562803

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..51

Formula

Empirical: a(n) = 8*a(n-1) -13*a(n-2) -54*a(n-3) +187*a(n-4) +44*a(n-5) -781*a(n-6) +486*a(n-7) +1514*a(n-8) -1663*a(n-9) -1455*a(n-10) +2317*a(n-11) +629*a(n-12) -1634*a(n-13) -68*a(n-14) +606*a(n-15) -22*a(n-16) -112*a(n-17) +4*a(n-18) +8*a(n-19)

Example

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

Crossrefs

Sequence in context: A044300 A044681 A250311 * A304674 A257524 A020256

Adjacent sequences: A211724 A211725 A211726 * A211728 A211729 A211730

Keyword

nonn

Author

R. H. Hardin Apr 20 2012

Status

approved