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 A093625 Primes of the form (3^m + 1)/2. 6
 2, 5, 41, 21523361, 926510094425921, 1716841910146256242328924544641 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes can only occur for m=2^k. The next term (if it exists) has k >= 21 (i.e., more than 10^6 decimal digits). - Don Reble, Apr 28 2004. [For the latest results about the search, see A171381. - N. J. A. Sloane, Jun 14 2010] LINKS EXAMPLE a(3)=41 because it can be written as (3^4 + 1)/2 = 82/2. CROSSREFS A171381 is the main entry for this sequence. Cf. also A059917, A138083. Sequence in context: A076725 A059917 A255963 * A042447 A176266 A075872 Adjacent sequences: A093622 A093623 A093624 * A093626 A093627 A093628 KEYWORD nonn,hard AUTHOR Hugo Pfoertner, Apr 19 2004 EXTENSIONS Erroneous terms deleted by N. J. A. Sloane, Jun 14 2010 STATUS approved

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Last modified December 10 02:09 EST 2022. Contains 358712 sequences. (Running on oeis4.)