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 A057941 Number of prime factors of 3^n + 1 (counted with multiplicity). 17
 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 Max Alekseyev, Table of n, a(n) for n = 1..691 (first 658 terms from Amiram Eldar) 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 bigomega(b^n+1): A057934 (b=10), A057935 (b=9), A057936 (b=8), A057937 (b=7), A057938 (b=6), A057939 (b=5), A057940 (b=4), this sequence (b=3), A054992 (b=2). Cf. A001222, A007658, A034472, A057958, A074476. Sequence in context: A076235 A268058 A334686 * A358550 A126071 A338292 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 June 15 02:47 EDT 2024. Contains 373402 sequences. (Running on oeis4.)