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A104483
Number of distinct prime divisors of 33...337 (with n 3s).
4
1, 1, 2, 3, 1, 3, 3, 2, 2, 2, 3, 3, 4, 4, 3, 4, 3, 3, 4, 5, 4, 4, 4, 4, 4, 5, 3, 4, 2, 4, 4, 5, 4, 4, 4, 8, 2, 2, 2, 3, 5, 4, 6, 6, 1, 5, 3, 4, 5, 4, 5, 8, 4, 2, 5, 5, 5, 2, 4, 4, 6, 4, 2, 4, 3, 4, 6, 3, 6, 9, 4, 7, 5, 3, 5, 7, 3, 6, 5, 6, 4, 7, 4, 5, 3, 5, 4
OFFSET
0,3
COMMENTS
Number of distinct prime factors of (10^(n + 1) - 1)/3 + 4. - Stefan Steinerberger, Mar 06 2006
LINKS
FORMULA
a(n) = A001221(A173766(n+1)). - Amiram Eldar, Jan 24 2020
EXAMPLE
The number of distinct prime divisors of 37 is 1 (prime).
The number of distinct prime divisors of 337 is 1 (prime).
The number of distinct prime divisors of 3337 is 2.
MATHEMATICA
Table[Length[FactorInteger[(10^(n + 1) - 1)/3 + 4]], {n, 1, 50}] (* Stefan Steinerberger, Mar 06 2006 *)
CROSSREFS
Sequence in context: A231633 A039702 A230294 * A080717 A239214 A200181
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Apr 18 2005
EXTENSIONS
More terms from Stefan Steinerberger, Mar 06 2006
More terms from Amiram Eldar, Jan 24 2020
STATUS
approved