|
|
A327734
|
|
Number of n-bead bracelet structures using exactly two different colored beads that are not self-equivalent under either a nonzero rotation or reversal (turning over bracelet).
|
|
2
|
|
|
0, 0, 0, 0, 0, 0, 1, 2, 7, 12, 31, 57, 126, 232, 484, 900, 1800, 3388, 6643, 12594, 24457, 46624, 90157, 172680, 333498, 641088, 1238664, 2388357, 4620006, 8931052
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,8
|
|
LINKS
|
|
|
EXAMPLE
|
Case n=7: There are 7 necklace structures using exactly two colors. See example in A056295. Of these, 5 are achiral and the other two a chiral pair: AAABABB/AAABBAB. a(7) = 1, since this sequence considers chiral pairs as the same bracelet structure.
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|