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A224073
Number of equivalence classes of words in F_2, modulo all automorphisms of F_2, whose minimal words have length n.
1
1, 1, 1, 1, 3, 4, 10, 16, 43, 101, 340, 911, 2544, 7224, 22616, 65376, 187754, 545743, 1653966, 4832057, 14027794
OFFSET
0,5
COMMENTS
F_2 is the free group on two generators.
LINKS
Bobbe Cooper and Eric Rowland, Growing words in the free group on two generators, Illinois Journal of Mathematics 55 (2011) 417-426.
Bobbe Cooper and Eric Rowland, Classification of automorphic conjugacy classes in the free group on two generators, Algorithmic Problems of Group Theory, Their Complexity, and Applications to Cryptography, edited by Delaram Kahrobaei and Vladimir Shpilrain, Contemporary Mathematics 633 (2015) 13-40.
CROSSREFS
A224074 is the number of root classes.
Sequence in context: A376816 A081160 A051437 * A034774 A342536 A172416
KEYWORD
nonn,hard
AUTHOR
Eric Rowland, Mar 30 2013
STATUS
approved