cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A079562 Number of distinct prime factors of n-th term of Look and Say Sequence A005150.

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%I A079562 #15 Apr 09 2022 06:37:23
%S A079562 0,1,2,2,2,1,1,4,2,2,4,3,3,5,7,7,7,5
%N A079562 Number of distinct prime factors of n-th term of Look and Say Sequence A005150.
%C A079562 a(16) >= 5. - _Nathaniel Johnston_, Nov 02 2010
%C A079562 a(18) >= 5. - _Giovanni Resta_, May 20 2020
%H A079562 Andy Huchala, <a href="/A079562/a079562.txt">Factors of A005150(n)</a>
%F A079562 a(n) = A001221(A005150(n)). - _Michel Marcus_, Apr 09 2022
%t A079562 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 *)
%Y A079562 Cf. A001221, A005150, A334132.
%K A079562 nonn,base,hard,more
%O A079562 1,3
%A A079562 _Joseph L. Pe_, Jan 25 2003
%E A079562 a(11)-a(15) from _Nathaniel Johnston_, Nov 02 2010
%E A079562 a(16)-a(17) from _Giovanni Resta_, May 20 2020
%E A079562 a(18) from _Andy Huchala_, Apr 08 2022