|
| |
|
|
A056331
|
|
Number of primitive (aperiodic) reversible string structures with n beads using a maximum of two different colors.
|
|
2
| |
|
|
1, 1, 2, 4, 9, 16, 35, 66, 133, 261, 527, 1032, 2079, 4123, 8244, 16440, 32895, 65639, 131327, 262380, 524762, 1049071, 2098175, 4195230, 8390646, 16779231, 33558392, 67112892, 134225919, 268443306
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
COMMENTS
| A string and its reverse are considered to be equivalent. Permuting the colors will not change the structure.
|
|
|
REFERENCES
| M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia.
|
|
|
FORMULA
| sum mu(d)*A005418(n/d) where d divides n.
|
|
|
CROSSREFS
| Cf. A045625.
Sequence in context: A005980 A128093 * A056336 A203318 A060401 A063981
Adjacent sequences: A056328 A056329 A056330 * A056332 A056333 A056334
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Marks R. Nester (nesterm(AT)dpi.qld.gov.au)
|
| |
|
|
