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 A209115 T(n,k) = number of n-bead necklaces labeled with numbers -k..k not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2. 13

%I

%S 1,1,2,1,3,1,1,4,5,5,1,5,11,22,5,1,6,19,55,63,15,1,7,29,120,261,238,

%T 25,1,8,41,221,741,1373,865,68,1,9,55,362,1683,5032,7377,3417,139,1,

%U 10,71,559,3325,14037,35253,41256,13607,354,1,11,89,816,5935,32802,121117,255821

%N T(n,k) = number of n-bead necklaces labeled with numbers -k..k not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.

%C Table starts

%C ..1....1.....1......1.......1.......1.......1........1........1.........1

%C ..2....3.....4......5.......6.......7.......8........9.......10........11

%C ..1....5....11.....19......29......41......55.......71.......89.......109

%C ..5...22....55....120.....221.....362.....559......816.....1137......1538

%C ..5...63...261....741....1683....3325....5935.....9835....15397.....23039

%C .15..238..1373...5032...14037...32802...67681...127310...222965....368920

%C .25..865..7377..35253..121117..336055..802125..1712987..3357255...6145113

%C .68.3417.41256.255821.1079992.3552027.9804610.23766209.52113718.105515163

%H R. H. Hardin, <a href="/A209115/b209115.txt">Table of n, a(n) for n = 1..165</a>

%e Some solutions for n=6, k=6:

%e .-3...-4...-5...-4...-6...-6...-5...-6...-5...-4...-2...-4...-3...-5...-4...-6

%e .-3...-1....1...-2...-2....0....2....2...-2...-2...-2...-3...-1...-1....2...-1

%e ..0...-2...-1....4....3....4...-2....0....5...-1...-2....1....0....4...-1....2

%e ..4....2....2....4...-1....0....5....6....4...-3....2....2....2...-2....3...-2

%e ..4....5....0...-1....0....4...-5....2...-2....6...-1....2....4....5....1....5

%e .-2....0....3...-1....6...-2....5...-4....0....4....5....2...-2...-1...-1....2

%Y Row 3 is A028387(n-1).

%K nonn,tabl

%O 1,3

%A _R. H. Hardin_, Mar 05 2012

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Last modified December 1 20:49 EST 2021. Contains 349435 sequences. (Running on oeis4.)