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A211570 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 three, four or five distinct values for every i,j,k<=n. 1
16, 28, 44, 74, 116, 194, 308, 518, 836, 1418, 2324, 3974, 6596, 11354, 19028, 32918, 55556, 96458, 163604, 284774, 484676, 845114, 1441748, 2516918, 4300676, 7513898, 12852884, 22467974, 38460356, 67256474, 115184468, 201474518, 345160196 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..64

FORMULA

Empirical: a(n) = a(n-1) + 5*a(n-2) - 5*a(n-3) - 6*a(n-4) + 6*a(n-5).

Empirical g.f.: 2*x*(8 + 6*x - 32*x^2 - 15*x^3 + 29*x^4) / ((1 - x)*(1 - 2*x^2)*(1 - 3*x^2)). - Colin Barker, Jul 19 2018

EXAMPLE

Some solutions for n=5:

.-2....0....0....1....0....2....1....0....1...-1...-1....0....1....0....1...-1

.-1....2...-2....0...-1....1....0....1....0....0...-2...-1....0....2....2....0

..0....0....0....1...-2....0....1....0....1....1...-1....0...-1....0....1...-1

..1...-2...-2....2...-1...-1....2....1....0....0....0....1....0....2....0....0

..2....0....0....1...-2...-2....1....0...-1...-1....1....2...-1....0...-1....1

..1...-2...-2....0...-1...-1....2...-2...-2...-2....2....1...-2...-1....0....0

CROSSREFS

Sequence in context: A166595 A280989 A337663 * A357264 A349418 A184031

Adjacent sequences: A211567 A211568 A211569 * A211571 A211572 A211573

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 16 2012

STATUS

approved

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Last modified December 6 12:26 EST 2022. Contains 358634 sequences. (Running on oeis4.)