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A202118 Number of -2..2 arrays of n elements with first, second and third differences also in -2..2 1
5, 19, 57, 127, 293, 663, 1517, 3459, 7905, 18051, 41239, 94203, 215217, 491661, 1123219, 2566023, 5862189, 13392389, 30595439, 69896451, 159681185, 364797903, 833395099, 1903923685, 4349588175, 9936804401, 22701018621, 51861365563 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A202124

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) +a(n-3) +3*a(n-4) -2*a(n-5) -3*a(n-6) -4*a(n-7) -3*a(n-8) -2*a(n-9) +3*a(n-10) +4*a(n-11) +2*a(n-12) for n>17

EXAMPLE

Some solutions for n=7

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A036421 A295776 A202658 * A327821 A201082 A109415

Adjacent sequences:  A202115 A202116 A202117 * A202119 A202120 A202121

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 11 2011

STATUS

approved

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Last modified September 24 23:43 EDT 2022. Contains 356951 sequences. (Running on oeis4.)