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 A270817 Integers n such that (2^n - 1) + (3^n - 1) + (5^n - 1) is a prime number. 0
 1, 3, 4, 9, 11, 69, 117, 449, 675, 1119, 1959, 2687, 2859 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Inspired by A268067. Corresponding primes are 7, 157, 719, 1973317, 49007317, ... LINKS EXAMPLE 4 is a term because (2^4 - 1) + (3^4 - 1) + (5^4 - 1) = 719 is a prime number. MATHEMATICA Select[Range@ 3000, PrimeQ[(2^# - 1) + (3^# - 1) + (5^# - 1)] &] (* Michael De Vlieger, Mar 23 2016 *) PROG (PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(-3 + 2^n + 3^n + 5^n), print1(n, ", "))); CROSSREFS Cf. A268064, A268067. Sequence in context: A054075 A062798 A327060 * A182828 A294229 A035256 Adjacent sequences:  A270814 A270815 A270816 * A270818 A270819 A270820 KEYWORD nonn,more AUTHOR Altug Alkan, Mar 23 2016 STATUS approved

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Last modified October 22 01:40 EDT 2020. Contains 337948 sequences. (Running on oeis4.)