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A237623
Two-Special Pairs in a Free Group
0
0, 0, 0, 0, 0, 1, 2, 6, 14, 30, 62, 129, 252, 499, 984, 1884, 3624, 7025, 13358, 25694, 49316
OFFSET
1,7
COMMENTS
a(n) is the number of pairs of positive words of length n in a free group of rank 2 such that the words are not conjugate and they have the same SL(2,C) trace functions. This sequence was discovered by Julian Caballero, Ruben Espinoza, Carlos Salinas under the supervision of Sean D Lawton.
CROSSREFS
Cf. A059076.
Sequence in context: A296965 A000918 A059076 * A232059 A343889 A263711
KEYWORD
nonn,more
AUTHOR
Sean D Lawton, Feb 10 2014
STATUS
approved