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%I #16 Apr 30 2018 13:24:08
%S 2,19,19,79,103,113,257,523,509,1151,1279,1193,1579,2273,3061,2389,
%T 2693,2843,5003,4831,5119,7411,5693,5623,8623,6323,10139,8933,18401,
%U 14957,20411,20479,21191,20123,29683,28211,36833,55021,57203,68743,48761,66533,62423
%N Primes of the form sigma(n) + phi(n), where sigma(n) = A000203(n) and phi(n) = A000010(n).
%e Third term of A038344 is 9 and sigma(9) + phi(9) = 13 + 6 = 19 is prime.
%p with(numtheory); P:=proc(q) local a, n; for n from 1 to q do a:=sigma(n)+phi(n);
%p if isprime(a) then print(a); fi; od; end: P(10^6);
%t Select[Table[DivisorSigma[1,n]+EulerPhi[n],{n,30000}],PrimeQ] (* _Harvey P. Dale_, Apr 30 2018 *)
%Y Cf. A000005, A000010, A000203, A009087, A023194, A038344, A055813, A062700, A064205, A115919, A141242, A229265-A229268
%K nonn
%O 1,1
%A _Paolo P. Lava_, Sep 18 2013
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