OFFSET
0,4
LINKS
Max Alekseyev, Table of n, a(n) for n = 0..331 [First 309 terms from Ray Chandler, from the Kamada link]
Makoto Kamada, Factorizations of 100...001.
FORMULA
EXAMPLE
a(1) = number of distinct prime factors of 11 = 1.
a(3) = number of distinct prime factors of 1001 = 3.
a(11) = 4 because 10^11+1 = 11*11*23*4093*8779 has 4 distinct factors.
MATHEMATICA
Table[Length[FactorInteger[10^n + 1]], {n, 0, 50}] (* Stefan Steinerberger, Jun 13 2006 *)
PrimeNu[10^Range[0, 100]+1] (* The program will take some time to run *) (* Harvey P. Dale, Aug 27 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Jun 09 2006
EXTENSIONS
More terms from Don Reble, Jun 13 2006
STATUS
approved