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 A089437 Numbers n such that 4^n + 3 is prime. 6
 1, 2, 3, 6, 8, 9, 14, 15, 42, 114, 195, 392, 555, 852, 1004, 1185, 2001, 2030, 2031, 2276, 8610, 8967, 10362, 11366, 15927, 16514, 17877, 19122, 19898, 27728, 29156, 61275, 102981, 117663, 181560, 239922, 342789 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The halved even terms of A057732. - R. J. Mathar, Feb 26 2008 LINKS EXAMPLE 4^15 + 3 = 1073741827 a prime number PROG (PARI) is(n)=ispseudoprime(4^n+3) \\ Charles R Greathouse IV, Feb 20 2017 CROSSREFS Cf. A228026 (the actual primes) Sequence in context: A111215 A099381 A289943 * A146768 A211370 A122479 Adjacent sequences:  A089434 A089435 A089436 * A089438 A089439 A089440 KEYWORD nonn AUTHOR Herman H. Rosenfeld (herm3(AT)pacbell.net), Dec 28 2003 EXTENSIONS More terms from Ray Chandler, Dec 30 2003 More terms from R. J. Mathar, Feb 26 2008 a(33)-a(38) derived from A057732 by Robert Price, Apr 26 2014 STATUS approved

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Last modified April 11 08:59 EDT 2021. Contains 342886 sequences. (Running on oeis4.)