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A015785
Phi(n) + 6 | sigma(n + 6).
4
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
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
KEYWORD
nonn
EXTENSIONS
Corrected by Charles R Greathouse IV, Sep 25 2012
STATUS
approved