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 A092590 a(n) = A065395(A000040(n)); values of commutator of sigma and phi function at prime number arguments. 1
 -1, 1, 5, 8, 14, 22, 25, 31, 28, 48, 56, 73, 78, 76, 56, 80, 74, 138, 112, 120, 159, 136, 102, 156, 210, 185, 168, 126, 240, 212, 248, 212, 226, 240, 226, 300, 314, 283, 204, 252, 222, 474, 296, 412, 339, 388, 472, 360, 270, 472, 378, 368, 634, 396, 427, 316, 404, 592, 534, 628, 436, 434, 582, 480, 684, 456, 700, 836 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The sequence differs from A065394 since it is not monotonic. LINKS EXAMPLE a(1) = sigma(phi(2))- phi(sigma(2)) = sigma(1)-phi(3) = 1-2 = -1. PROG (MAGMA) [DivisorSigma(1, EulerPhi(p))-EulerPhi(DivisorSigma(1, p)): p in PrimesUpTo(400)]; // Bruno Berselli, Oct 20 2015 CROSSREFS Cf. A000010, A000040, A000203, A033632, A065393-A065395, A092584-A092589. Sequence in context: A314524 A314525 A314526 * A065394 A124011 A101835 Adjacent sequences:  A092587 A092588 A092589 * A092591 A092592 A092593 KEYWORD sign,look AUTHOR Labos Elemer, Mar 03 2004 STATUS approved

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Last modified April 11 06:40 EDT 2021. Contains 342886 sequences. (Running on oeis4.)