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A200195
Number of -n..n arrays x(0..5) of 6 elements with zero sum, adjacent elements differing by more than one, and elements alternately increasing and decreasing.
1
2, 54, 482, 2240, 7266, 18838, 41938, 83600, 153278, 263198, 428718, 668684, 1005790, 1466934, 2083578, 2892104, 3934174, 5257082, 6914122, 8964936, 11475878, 14520370, 18179258, 22541172, 27702886, 33769670, 40855654, 49084180
OFFSET
1,1
COMMENTS
Row 6 of A200192.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -2*a(n-2) -a(n-3) +2*a(n-5) -a(n-6) -a(n-7) +2*a(n-8) -a(n-10) -2*a(n-11) +3*a(n-12) -a(n-13).
Empirical g.f.: 2*x*(1 + 24*x + 162*x^2 + 452*x^3 + 782*x^4 + 999*x^5 + 1045*x^6 + 910*x^7 + 622*x^8 + 292*x^9 + 74*x^10 + 5*x^11) / ((1 - x)^6*(1 + x)*(1 + x + x^2)*(1 + x + x^2 + x^3 + x^4)). - Colin Barker, May 20 2018
EXAMPLE
Some solutions for n=5:
..1...-5...-5....3...-4....0....0...-2...-3....2....4....3...-4...-4...-1....0
.-5....0....4...-2....3...-5...-3....1...-1...-1...-4...-3....4....5...-3....4
..0...-5...-3....3...-1....4....5...-5...-4....4....4....3...-3...-5....5...-3
.-4....5....5...-4....4...-3...-3....5....4...-4...-4...-3....0....3...-5...-1
..5....1...-2....1...-5....3....3...-1...-1....3....1....5...-2...-2....5...-4
..3....4....1...-1....3....1...-2....2....5...-4...-1...-5....5....3...-1....4
CROSSREFS
Cf. A200192.
Sequence in context: A078691 A280754 A113028 * A202739 A055024 A057411
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 14 2011
STATUS
approved