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A208805 T(n,k) = number of n-bead necklaces labeled with numbers -k..k allowing reversal, with sum zero and three times sum of squares <= n*k*(k+1). 9
1, 1, 1, 1, 2, 2, 1, 3, 4, 3, 1, 3, 5, 11, 3, 1, 4, 8, 24, 33, 15, 1, 4, 12, 50, 99, 105, 22, 1, 5, 17, 84, 239, 518, 395, 38, 1, 5, 22, 136, 561, 1746, 2782, 1612, 147, 1, 6, 25, 201, 1073, 4566, 11557, 15485, 6323, 296, 1, 7, 31, 278, 1827, 10372, 38668, 82577, 88835, 27727 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

..1....1.....1.....1......1.......1.......1.......1........1........1.......1

..1....2.....3.....3......4.......4.......5.......5........6........7.......7

..2....4.....5.....8.....12......17......22......25.......31.......38......45

..3...11....24....50.....84.....136.....201.....278......386......519.....670

..3...33....99...239....561....1073....1827....3079.....4801.....7043...10225

.15..105...518..1746...4566...10372...21227...39191....68069...112194..176414

.22..395..2782.11557..38668..105147..243678..521213..1008722..1833875.3177066

.38.1612.15485.82577.347219.1111859.2951235.7202490.15635629.31151165

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..148

EXAMPLE

Some solutions for n=6, k=2:

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

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

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

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

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

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

CROSSREFS

Sequence in context: A061987 A323899 A182630 * A208514 A179901 A209561

Adjacent sequences:  A208802 A208803 A208804 * A208806 A208807 A208808

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 01 2012

STATUS

approved

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Last modified April 17 22:48 EDT 2021. Contains 343071 sequences. (Running on oeis4.)