A208721 T(n,k) = number of n-bead necklaces labeled with numbers 1..k allowing reversal, with no adjacent beads differing by more than 1.

1, 2, 1, 3, 3, 1, 4, 5, 4, 1, 5, 7, 7, 6, 1, 6, 9, 10, 12, 8, 1, 7, 11, 13, 18, 18, 13, 1, 8, 13, 16, 24, 28, 34, 18, 1, 9, 15, 19, 30, 38, 56, 56, 30, 1, 10, 17, 22, 36, 48, 78, 98, 111, 46, 1, 11, 19, 25, 42, 58, 100, 140, 208, 207, 78, 1, 12, 21, 28, 48, 68, 122, 182, 306, 418, 427, 126

Offset: 1

Author

R. H. Hardin, Mar 01 2012

Keywords

• nonn
• tabl

Comments

Table starts

.1..2...3...4...5...6...7...8...9..10..11..12...13...14...15...16...17...18

.1..3...5...7...9..11..13..15..17..19..21..23...25...27...29...31...33...35

.1..4...7..10..13..16..19..22..25..28..31..34...37...40...43...46...49...52

.1..6..12..18..24..30..36..42..48..54..60..66...72...78...84...90...96..102

.1..8..18..28..38..48..58..68..78..88..98.108..118..128..138..148..158..168

.1.13..34..56..78.100.122.144.166.188.210.232..254..276..298..320..342..364

.1.18..56..98.140.182.224.266.308.350.392.434..476..518..560..602..644..686

.1.30.111.208.306.404.502.600.698.796.894.992.1090.1188.1286.1384.1482.1580

Examples

			All solutions for n=4, k=3:
..2....3....2....2....1....2....1....2....1....1....1....1
..3....3....2....3....1....2....1....2....2....2....1....2
..2....3....3....3....2....2....1....2....1....3....1....2
..3....3....3....3....2....2....1....3....2....2....2....2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..397

Crossrefs

Column 2 is A000029.