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 A113913 Number of distinct prime factors of 3^(3^n)+1. 1
 1, 2, 4, 6, 11, 20, 27 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The term omega(3^(3^6)+1) was obtained with ECM factoring. LINKS FORMULA a(n) = A001221(A129290(n)). MATHEMATICA Table[PrimeNu[3^(3^n) + 1], {n, 1, 10}] (* G. C. Greubel, May 16 2017 *) PROG (PARI) for(x=1, 6, print1( omega(3^(3^x)+1), ", ")) CROSSREFS Sequence in context: A000694 A164137 A018170 * A002097 A026757 A026385 Adjacent sequences:  A113910 A113911 A113912 * A113914 A113915 A113916 KEYWORD hard,more,nonn AUTHOR Jorge Coveiro, Jan 29 2006 STATUS approved

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Last modified April 22 11:46 EDT 2019. Contains 322330 sequences. (Running on oeis4.)