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A077636
Length of periodic part of continued fraction expansion of square root of A051451(n), i.e., sqrt(lcm(1..x)) where x is a prime power from A000961.
3
0, 1, 2, 2, 4, 2, 2, 2, 4, 8, 18, 14, 36, 38, 232, 268, 110, 280, 4348, 3244, 32684, 148184, 207616, 9988, 1946132, 2154482, 13319736, 8971624, 12345748, 69705504, 159413696, 1184191340, 1183672188, 23656693528, 28963250020, 701296434876, 754283490078
OFFSET
1,3
FORMULA
a(n) = A003285(A051451(n)). - Michel Marcus, Sep 30 2019
EXAMPLE
For A051451(10) = 360360, the periodic part is {3,2,1,132,1,2,3,1200} with 8 terms, so a(10) = 8.
MATHEMATICA
pp = Join[{1}, Select[Range[2, 50], Mod[ #, # - EulerPhi[ # ]] == 0 &]]; Table[ Length[ Last[ ContinuedFraction[ Sqrt[ Apply[ LCM, Table[i, {i, 1, pp[[n]]}]]]]]], {n, 1, 31}]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Labos Elemer, Nov 13 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, Nov 14 2002
a(31) from Ray Chandler, Jan 16 2009
a(32)-a(35) from Chai Wah Wu, Sep 26 2019
a(36) from Chai Wah Wu, Sep 29 2019
a(37) from Chai Wah Wu, Sep 26 2021
STATUS
approved