A211589 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, three, four, six or eight distinct values for every i,j,k<=n

24, 80, 226, 596, 1536, 3966, 10192, 26572, 69102, 182368, 479844, 1278318, 3393724, 9100172, 24316814, 65498292, 175852800, 475172186, 1280321244, 3467619648, 9369009790, 25419829164, 68829542860, 187003542158, 507226552512

Offset

1,1

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -6*a(n-2) -60*a(n-3) +139*a(n-4) +94*a(n-5) -507*a(n-6) +148*a(n-7) +690*a(n-8) -428*a(n-9) -372*a(n-10) +272*a(n-11) +72*a(n-12) -48*a(n-13)

Example

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

Crossrefs

Sequence in context: A167561 A211575 A211583 * A211597 A318988 A182915

Adjacent sequences: A211586 A211587 A211588 * A211590 A211591 A211592

Keyword

nonn

Author

R. H. Hardin Apr 16 2012

Status

approved