A015785 Phi(n) + 6 | sigma(n + 6).

9, 18, 20, 27, 28, 52, 54, 68, 76, 81, 104, 116, 126, 130, 162, 172, 188, 212, 228, 243, 258, 268, 292, 350, 356, 362, 388, 452, 486, 508, 520, 548, 556, 594, 628, 668, 692, 772, 780, 788, 796, 892, 908, 916, 1026, 1076, 1108, 1132, 1228, 1348

Offset

1,1

Links

Table of n, a(n) for n=1..50.

Mathematica

Select[Range[1400], Divisible[DivisorSigma[1, #+6], EulerPhi[#]+6]&] (* Harvey P. Dale, Mar 06 2019 *)

Prog

(PARI) is(n)=!(sigma(n+6)%(eulerphi(n)+6)) \\ Charles R Greathouse IV, Sep 25 2012

Crossrefs

Sequence in context: A092457 A062057 A254066 * A366290 A316438 A208135

Adjacent sequences: A015782 A015783 A015784 * A015786 A015787 A015788

Keyword

nonn

Author

Robert G. Wilson v

Extensions

Corrected by Charles R Greathouse IV, Sep 25 2012

Status

approved