A211725 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, three, four or five distinct values for every i,j,k<=n.

37, 79, 145, 289, 549, 1083, 2101, 4151, 8145, 16131, 31837, 63151, 125013, 248203, 492161, 977771, 1940909, 3858087, 7664741, 15243819, 30305953, 60305099, 119969501, 238849543, 475449301, 947060219, 1886258177, 3759082587

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 6*a(n-2) - 23*a(n-3) - 9*a(n-4) + 62*a(n-5) - 2*a(n-6) - 74*a(n-7) + 10*a(n-8) + 40*a(n-9) - 4*a(n-10) - 8*a(n-11).

Empirical g.f.: x*(37 - 32*x - 314*x^2 + 231*x^3 + 962*x^4 - 546*x^5 - 1314*x^6 + 484*x^7 + 784*x^8 - 140*x^9 - 168*x^10) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - x - x^2)*(1 - 2*x^2)*(1 - 4*x^2 + 2*x^4)). - Colin Barker, Jul 20 2018

Example

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

Crossrefs

Sequence in context: A298324 A346559 A256585 * A141895 A262566 A323428

Adjacent sequences: A211722 A211723 A211724 * A211726 A211727 A211728

Keyword

nonn

Author

R. H. Hardin, Apr 20 2012

Status

approved