A015825 Numbers k such that phi(k + 8) | sigma(k).

6, 7, 10, 30, 41, 46, 54, 55, 62, 66, 70, 78, 108, 114, 118, 132, 135, 138, 168, 174, 186, 188, 190, 195, 220, 246, 286, 297, 318, 354, 357, 378, 382, 391, 434, 438, 460, 474, 510, 534, 553, 606, 618, 646, 654, 667, 702, 748, 754, 780, 786, 834, 836, 852

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..2000

Mathematica

Select[Range[1000], Divisible[DivisorSigma[1, #], EulerPhi[8 + #]] &] (* David Nacin, Mar 01 2012 *)

Prog

(PARI) is(n)=sigma(n)%(eulerphi(n)+8)==0 \\ Charles R Greathouse IV, Sep 25 2012

Crossrefs

Cf. A000010 (phi), A000203 (sigma).

Sequence in context: A114949 A081359 A117618 * A243489 A164018 A156793

Adjacent sequences: A015822 A015823 A015824 * A015826 A015827 A015828

Keyword

nonn

Author

Robert G. Wilson v

Status

approved