OFFSET
1
COMMENTS
An invertible necklace on the alphabet {0,1} is an equivalence class of binary strings where two strings are considered the same if (1) one string can be rotated to form the other or (2) swapping the 0s and 1s in one string results in the other string.
There are A000013(n) rows of length n.
EXAMPLE
Table begins:
0,
0, 0,
0, 1,
0, 0, 0,
0, 0, 1,
0, 0, 0, 0,
0, 0, 0, 1,
0, 0, 1, 1,
0, 1, 0, 1,
0, 0, 0, 0, 0,
0, 0, 0, 0, 1,
0, 0, 0, 1, 1,
0, 0, 1, 0, 1,
0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 1, 1,
0, 0, 0, 1, 0, 1,
0, 0, 0, 1, 1, 1,
0, 0, 1, 0, 0, 1,
0, 0, 1, 0, 1, 1,
0, 1, 0, 1, 0, 1,
...
"0,0,1,1,1" is not a a row in this table because 0,0,1,1,1 = 1,1,0,0,0 = 0,0,0,1,1 and 0,0,0,1,1 is lexicographically earlier.
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Peter Kagey, Sep 04 2022
STATUS
approved