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 A292763 Numbers m such that sigma(m)+phi(m) == 2 mod 4. 1
 1, 3, 5, 6, 7, 10, 11, 13, 14, 17, 19, 20, 22, 23, 26, 27, 29, 31, 34, 37, 38, 40, 41, 43, 45, 46, 47, 52, 53, 54, 58, 59, 61, 62, 67, 68, 71, 73, 74, 79, 80, 82, 83, 86, 89, 90, 94, 97, 101, 103, 104, 106, 107, 109, 113, 116, 117, 118, 122, 127, 131, 134, 136, 137, 139, 142, 146, 148, 149, 151, 153, 157 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Union of {1}, A191217 and A292762. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..5000 N. J. A. Sloane, Three (No, 8) Lovely Problems from the OEIS, Experimental Mathematics Seminar, Rutgers University, Oct 05 2017, Part I, Part 2, Slides. (Mentions this sequence) MATHEMATICA Do[If[Mod[DivisorSigma[1, n] + EulerPhi[n], 4]==2, Print[n]], {n, 1, 10^3}] (* Vincenzo Librandi, Oct 02 2017 *) PROG (PARI) isok(m) = ((sigma(m)+eulerphi(m)) % 4) == 2; \\ Michel Marcus, Oct 02 2017 CROSSREFS Cf. A000010, A000203. Cf. A191217, A292762. A065091 (odd primes) is a subsequence. - Michel Marcus, Oct 02 2017 Sequence in context: A182851 A281995 A304452 * A176175 A157201 A067351 Adjacent sequences:  A292760 A292761 A292762 * A292764 A292765 A292766 KEYWORD nonn AUTHOR N. J. A. Sloane, Sep 26 2017 STATUS approved

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Last modified April 20 16:04 EDT 2021. Contains 343135 sequences. (Running on oeis4.)