

A102246


Number of distinct prime factors of prime p concatenated p1 times.


1



1, 2, 3, 5, 7, 9, 10, 10, 10, 11, 19, 16, 14, 20, 9, 12
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


LINKS



EXAMPLE

If p=2, then the number of distinct prime factors of 2 is 1 since 2 is prime.
If p=3, then the number of distinct prime factors of 33 is 2.
If p=5, then the number of distinct prime factors of 5555 is 3.
If p=7, then the number of distinct prime factors of 777777 is 5.


MATHEMATICA

f[n_] := Length[ FactorInteger[ FromDigits[ Flatten[ Table[ IntegerDigits[ Prime[n]], {Prime[n]  1}]] ]]]; Table[ f[n], {n, 10}]
dpf[n_]:=Module[{p=Prime[n]}, PrimeNu[FromDigits[Flatten[ IntegerDigits/@ Table[p, {p1}]]]]]; Array[dpf, 16] (* Harvey P. Dale, Aug 20 2013 *)


CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



