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%I #16 Dec 02 2015 12:23:53
%S 1,2,3,4,5,6,7,12,45,64,121,144,238,261,415,2296,2847
%N Integers n such that A002110(n) + A006450(n) is prime.
%C Corresponding primes are 5, 11, 41, 227, 2341 and 30071.
%C 1, 4, 64, 121, 144 are squares for initial terms of sequence. Are there any other squares in this sequence?
%e a(1) = 1 because 2 + 3 = 5 is prime.
%e a(2) = 2 because 2*3 + 5 = 11 is prime.
%e a(3) = 3 because 2*3*5 + 11 = 41 is prime.
%t Select[Range@ 500, PrimeQ[Product[Prime@ k, {k, #}] + Prime@ Prime@ #] &] (* _Michael De Vlieger_, Dec 02 2015 *)
%o (PARI) lista(nn) = {s = 1; for(k=1, nn, s *= prime(k); if(ispseudoprime(s + prime(prime(k))), print1(k, ", ")); ); }
%Y Cf. A002110, A006450.
%K nonn,more
%O 1,2
%A _Altug Alkan_, Dec 02 2015
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