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A079562
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Number of distinct prime factors of n-th term of Look and Say Sequence A005150.
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7
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0, 1, 2, 2, 2, 1, 1, 4, 2, 2, 4, 3, 3, 5, 7, 7, 7, 5
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,3
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COMMENTS
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LINKS
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FORMULA
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MATHEMATICA
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s[1]=1; s[n_] := s[n] = FromDigits[ Flatten[{ IntegerDigits@ Length@ #, First@ #} & /@ Split[ IntegerDigits@ s[n-1] ]]]; PrimeNu /@ s /@ Range[15] (* Giovanni Resta, May 20 2020 *)
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CROSSREFS
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KEYWORD
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nonn,base,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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