OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..199
FORMULA
EXAMPLE
The number of distinct prime divisors of 53 is 1 (prime) which is the first term in the sequence.
The number of distinct prime divisors of 553 is 2 which is the second term in the sequence.
The number of distinct prime divisors of 5553 is 2 which is the third term in the sequence.
MAPLE
A104518 := proc(n) local x ; x := [3, seq(5, k=1..n)] ; add(op(i, x)*10^(i-1), i=1..nops(x)) ; numtheory[factorset](%) ; nops(%) ; end proc: # R. J. Mathar, Aug 24 2011
MATHEMATICA
Table[PrimeNu[(50*10^n - 23)/9], {n, 0, 50}] (* G. C. Greubel, May 06 2017 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Apr 19 2005
EXTENSIONS
More terms from Amiram Eldar, Jan 25 2020
STATUS
approved