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%I #7 Nov 04 2013 21:16:02
%S 2,3,5,7,13,19,23,37,47,31,67,109,71,79,139,127,139,163,227,199,443,
%T 379,313,271,547,367,619,547,593,643,523,739,619,1093,883,691,907,787,
%U 1153,787,787,787,1867,1327,1987,1231,1487,1487,2731,2659,2551,4327,4231
%N Primes expressible as phi(sigma(n)) + sigma(phi(n)), in order of their occurrence.
%H K. D. Bajpai, <a href="/A231099/b231099.txt">Table of n, a(n) for n = 1..3500</a>
%e a(6)= 19: phi(sigma(12)) + sigma(phi(12))= 12+7= 19 which is prime.
%e a(9)= 47: phi(sigma(19)) + sigma(phi(19))= 8+39= 47 which is prime.
%p with(numtheory): KD:= proc() local a; a:= phi(sigma(n))+sigma(phi(n)); if isprime(a) then return (a) : fi; end: seq(KD(), n=1..10000);
%Y Cf. A062401 (phi(sigma(n))).
%Y Cf. A062402 (sigma(phi(n))).
%K nonn,less
%O 1,1
%A _K. D. Bajpai_, Nov 03 2013
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