Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%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_