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A015875 Numbers k such that phi(k + 12) | sigma(k) + 12. 1

%I #17 Jan 25 2024 05:27:53

%S 3,6,10,12,14,15,22,24,26,30,34,42,44,46,62,69,74,82,94,106,114,118,

%T 122,134,135,146,166,194,198,202,206,214,262,282,302,314,334,346,366,

%U 382,386,446,454,466,474,502,514,526,542,554,614,622,662,694

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

%H Harvey P. Dale, <a href="/A015875/b015875.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[700],Divisible[DivisorSigma[1,#]+12,EulerPhi[#+12]]&] (* _Harvey P. Dale_, Apr 14 2021 *)

%o (PARI) is(n)=!((sigma(n)+12)%eulerphi(n+12)) \\ _Charles R Greathouse IV_, Sep 25 2012

%Y Cf. A000010, A000203.

%K nonn

%O 1,1

%A _Robert G. Wilson v_

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Last modified March 29 00:26 EDT 2024. Contains 371264 sequences. (Running on oeis4.)