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%I #14 Jan 24 2022 12:46:24
%S 7,10,14,21,26,34,38,58,86,93,94,106,134,146,178,194,226,254,274,278,
%T 314,334,346,357,381,386,394,398,446,454,458,538,554,566,614,674,681,
%U 698,706,758,766,794,818,878,926,934,974,1006,1018,1046
%N Numbers k such that phi(k) + 3 | sigma(k + 3).
%H Robert Israel, <a href="/A015782/b015782.txt">Table of n, a(n) for n = 1..10000</a>
%p filter:= proc(n) uses numtheory;
%p sigma(n+3) mod (3+phi(n)) = 0
%p end proc:
%p select(filter, [$1..2000]); # _Robert Israel_, Jan 24 2022
%t Select[Range[1100],Divisible[DivisorSigma[1,#+3],EulerPhi[#]+3]&] (* _Harvey P. Dale_, Sep 04 2013 *)
%o (PARI) is(n)=!(sigma(n+3)%(eulerphi(n)+3)) \\ _Charles R Greathouse IV_, Sep 25 2012
%Y Cf. A000010, A000203.
%K nonn
%O 1,1
%A _Robert G. Wilson v_
%E Corrected by _Charles R Greathouse IV_, Sep 25 2012
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