A015875 - OEIS

A015875

Numbers k such that phi(k + 12) | sigma(k) + 12.

3, 6, 10, 12, 14, 15, 22, 24, 26, 30, 34, 42, 44, 46, 62, 69, 74, 82, 94, 106, 114, 118, 122, 134, 135, 146, 166, 194, 198, 202, 206, 214, 262, 282, 302, 314, 334, 346, 366, 382, 386, 446, 454, 466, 474, 502, 514, 526, 542, 554, 614, 622, 662, 694

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OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Range[700], Divisible[DivisorSigma[1, #]+12, EulerPhi[#+12]]&] (* Harvey P. Dale, Apr 14 2021 *)

PROG

(PARI) is(n)=!((sigma(n)+12)%eulerphi(n+12)) \\ Charles R Greathouse IV, Sep 25 2012

CROSSREFS

Cf. A000010, A000203.

Sequence in context: A345915 A050107 A120068 * A301285 A310042 A310043

Adjacent sequences: A015872 A015873 A015874 * A015876 A015877 A015878

KEYWORD

nonn

AUTHOR

Robert G. Wilson v

STATUS

approved