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A105068
Number of distinct prime divisors of 10^n - 3.
4
1, 1, 1, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 4, 4, 1, 4, 5, 4, 2, 2, 4, 2, 2, 3, 4, 3, 4, 3, 6, 4, 3, 2, 4, 4, 5, 3, 5, 5, 4, 5, 7, 4, 5, 4, 7, 5, 4, 4, 5, 4, 3, 2, 4, 4, 2, 5, 5, 4, 4, 3, 3, 4, 2, 3, 5, 5, 6, 5, 4, 3, 3, 5, 6, 5, 5, 4, 7, 4, 3, 5, 4, 5, 5, 2, 6
OFFSET
1,4
LINKS
FORMULA
a(n) = A001221(A173833(n)). - Amiram Eldar, Jan 25 2020
EXAMPLE
If n = 1, 2 or 3, then 10^n - 3 is prime and thus the first three terms are 1.
MATHEMATICA
Table[Length[FactorInteger[10^n - 3]], {n, 1, 50}] (* Stefan Steinerberger, Feb 21 2006 *)
CROSSREFS
Sequence in context: A078178 A306396 A355035 * A363274 A120676 A184172
KEYWORD
nonn
AUTHOR
Parthasarathy Nambi, Apr 05 2005
EXTENSIONS
More terms from Stefan Steinerberger, Feb 21 2006
More terms from Amiram Eldar, Jan 25 2020
STATUS
approved