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 A138789 a(n) = number of distinct prime divisors of A104759(n). 17
 0, 2, 2, 2, 3, 2, 2, 3, 3, 2, 2, 4, 4, 2, 5, 4, 2, 3, 7, 4, 4, 3, 3, 2, 5, 3, 5, 2, 3, 6, 6, 3, 3, 5, 5, 7, 3, 3, 4, 3, 3, 4, 4, 5, 3, 5, 7, 3, 5, 6, 6, 5, 4, 5, 2, 6, 4, 6, 4, 4, 7, 6, 5, 5, 6, 9 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Indices where number 1 occured in this sequence see A138790 LINKS MATHEMATICA lst = {}; Do[lst = Join[lst, IntegerDigits[n]], {n, 1, 50}]; Table[Length[FactorInteger[FromDigits[Reverse[lst[[Range[1, n]]]]]]], {n, 1, Length[lst]}] (* Robert Price, Mar 24 2015 *) CROSSREFS Cf. A000422, A116504, A007908, A116505, A007878, A138787. Sequence in context: A053760 A223942 A278597 * A129654 A116504 A186233 Adjacent sequences:  A138786 A138787 A138788 * A138790 A138791 A138792 KEYWORD nonn,base AUTHOR Artur Jasinski, Mar 30 2008 EXTENSIONS Entire sequence corrected by Robert Price, Mar 24 2015 STATUS approved

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Last modified August 26 02:19 EDT 2019. Contains 326324 sequences. (Running on oeis4.)