A211571 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 or five distinct values for every i,j,k<=n.

24, 60, 136, 278, 564, 1102, 2160, 4170, 8084, 15586, 30160, 58306, 113060, 219478, 427124, 832842, 1627284, 3186354, 6249740, 12283214, 24175236, 47665998, 94090952, 186015186, 368095480, 729323938, 1446163736, 2870526594, 5701393800

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..37

Formula

Empirical: a(n) = 5*a(n-1) - a(n-2) - 31*a(n-3) + 39*a(n-4) + 56*a(n-5) - 116*a(n-6) - 14*a(n-7) + 115*a(n-8) - 34*a(n-9) - 30*a(n-10) + 12*a(n-11).

Empirical g.f.: 2*x*(12 - 30*x - 70*x^2 + 201*x^3 + 117*x^4 - 454*x^5 - 24*x^6 + 397*x^7 - 76*x^8 - 99*x^9 + 34*x^10) / ((1 - x)*(1 - 2*x)*(1 - x - x^2)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - x - 2*x^2 + x^3)). - Colin Barker, Jul 19 2018

Example

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

Crossrefs

Sequence in context: A356892 A370990 A182464 * A240524 A250577 A242844

Adjacent sequences: A211568 A211569 A211570 * A211572 A211573 A211574

Keyword

nonn

Author

R. H. Hardin, Apr 16 2012

Status

approved