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 A057941 Number of prime factors of 3^n + 1 (counted with multiplicity). 10
 2, 2, 3, 2, 3, 3, 3, 3, 5, 4, 4, 3, 3, 4, 6, 2, 5, 4, 4, 3, 7, 4, 3, 6, 5, 4, 7, 4, 5, 6, 4, 2, 7, 4, 5, 4, 5, 4, 8, 5, 4, 7, 3, 5, 10, 4, 5, 4, 5, 8, 9, 4, 4, 5, 7, 6, 8, 4, 4, 7, 4, 5, 13, 2, 5, 6, 4, 5, 9, 9, 7, 8, 4, 5, 12, 6, 6, 7, 5, 5, 12, 5, 6, 10, 9, 7, 11, 6, 5, 9, 8, 4, 9, 4, 8, 6, 5, 9, 14, 6, 4 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..658 S. S. Wagstaff, Jr., The Cunningham Project FORMULA a(n) = A057958(2n) - A057958(n) - T. D. Noe, Jun 19 2003 a(n) = A001222(A034472(n)). - Amiram Eldar, Feb 01 2020 MATHEMATICA PrimeOmega[3^Range[110]+1] (* Harvey P. Dale, Jun 20 2015 *) PROG (PARI) a(n)=bigomega(n^3+1) \\ Charles R Greathouse IV, Sep 14 2015 CROSSREFS Cf. A001222, A007658, A034472, A057934-A057940, A054992, A057958. Sequence in context: A076235 A268058 A334686 * A126071 A338292 A217865 Adjacent sequences:  A057938 A057939 A057940 * A057942 A057943 A057944 KEYWORD nonn AUTHOR Patrick De Geest, Oct 15 2000 STATUS approved

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Last modified April 16 15:47 EDT 2021. Contains 343050 sequences. (Running on oeis4.)