A015784 Phi(n) + 5 | sigma(n + 5).

1, 5, 12, 60, 68, 92, 123, 131, 188, 236, 332, 404, 428, 452, 596, 668, 764, 932, 1004, 1028, 1124, 1244, 1604, 1772, 1796, 1868, 2012, 2084, 2276, 2372, 2468, 2588, 2612, 2708, 3044, 3308, 3356, 3428, 3452, 3524, 3764, 3788, 3884, 4052, 4124

Offset

1,2

Links

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

Mathematica

Select[Range[4200], Divisible[DivisorSigma[1, #+5], EulerPhi[#]+5]&] (* Harvey P. Dale, May 09 2019 *)

Prog

(PARI) is(n)=!(sigma(n+5)%(eulerphi(n)+5)) \\ Charles R Greathouse IV, Sep 25 2012

Crossrefs

Sequence in context: A342549 A346746 A111904 * A302182 A363452 A129723

Adjacent sequences: A015781 A015782 A015783 * A015785 A015786 A015787

Keyword

nonn

Author

Robert G. Wilson v

Extensions

Corrected by Charles R Greathouse IV, Sep 25 2012

Status

approved