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 A265124 Integers n such that A002110(n) + A006450(n) is prime. 0
 1, 2, 3, 4, 5, 6, 7, 12, 45, 64, 121, 144, 238, 261, 415, 2296, 2847 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Corresponding primes are 5, 11, 41, 227, 2341 and 30071. 1, 4, 64, 121, 144 are squares for initial terms of sequence. Are there any other squares in this sequence? LINKS EXAMPLE a(1) = 1 because 2 + 3 = 5 is prime. a(2) = 2 because 2*3 + 5 = 11 is prime. a(3) = 3 because 2*3*5 + 11 = 41 is prime. MATHEMATICA Select[Range@ 500, PrimeQ[Product[Prime@ k, {k, #}] + Prime@ Prime@ #] &] (* Michael De Vlieger, Dec 02 2015 *) PROG (PARI) lista(nn) = {s = 1; for(k=1, nn, s *= prime(k); if(ispseudoprime(s + prime(prime(k))), print1(k, ", ")); ); } CROSSREFS Cf. A002110, A006450. Sequence in context: A173819 A165305 A125745 * A032990 A060810 A319723 Adjacent sequences:  A265121 A265122 A265123 * A265125 A265126 A265127 KEYWORD nonn,more AUTHOR Altug Alkan, Dec 02 2015 STATUS approved

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Last modified July 24 02:42 EDT 2019. Contains 325287 sequences. (Running on oeis4.)