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A319214
a(n) = phi(n^5 - 1)/5 where phi is A000010.
4
6, 22, 120, 280, 1240, 1120, 5400, 5280, 12960, 12880, 45240, 24752, 90240, 59160, 96000, 141984, 346880, 163800, 540000, 326720, 588984, 585120, 1523280, 582400, 1728000, 1203840, 2294712, 1758096, 4692408, 1388000, 6480000, 3787200, 5416800, 4783680, 7440000
OFFSET
2,1
LINKS
Eric Weisstein's World of Mathematics, Totient Function.
MATHEMATICA
Table[EulerPhi[n^5-1]/5, {n, 2, 40}] (* Harvey P. Dale, Feb 09 2019 *)
PROG
(PARI) {a(n) = eulerphi(n^5-1)/5}
CROSSREFS
Row 5 of A369291.
Cf. A000010, A258807 (n^5-1).
phi(n^b - 1)/b: A319210 (b=2), A319213 (b=3), this sequence (b=5).
Sequence in context: A179601 A151495 A193463 * A009358 A213130 A002137
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 13 2018
STATUS
approved