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 A299642 Numbers k such that 2^k + 5*k is a prime. 2
 1, 3, 7, 9, 15, 21, 33, 37, 61, 141, 159, 229, 345, 373, 511, 717, 2065, 2337, 15619, 22771, 22875, 23911, 29323 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(19) = 15619 corresponds to a probable prime. - Jon E. Schoenfield, Feb 28 2018 LINKS MAPLE a:=n->`if`(isprime(2^n+5*n), n, NULL): seq(a(n), n=1..7000); # Muniru A Asiru, Mar 10 2018 MATHEMATICA Select[Range[7000], PrimeQ[2^# + 5 #] &] PROG (MAGMA) [n: n in [0..2000] |IsPrime(2^n+5*n)]; (PARI) isok(k) = isprime(2^k + 5*k); \\ Altug Alkan, Mar 03 2018 CROSSREFS Cf. A297663. Sequence in context: A261871 A191131 A282572 * A128539 A192118 A282534 Adjacent sequences:  A299639 A299640 A299641 * A299643 A299644 A299645 KEYWORD nonn,more AUTHOR Vincenzo Librandi, Feb 28 2018 EXTENSIONS a(19) from Jon E. Schoenfield, Feb 28 2018 a(20)-a(23) from Daniel Suteu, Mar 11 2018 STATUS approved

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Last modified January 16 18:17 EST 2022. Contains 350376 sequences. (Running on oeis4.)