OFFSET
1,3
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..352 (first 322 terms from Ray Chandler)
Eric Weisstein's World of Mathematics, Repunit.
FORMULA
a(n) = A057951(n) - 2. - Ray Chandler, Apr 24 2017
EXAMPLE
R(6) = 111111 = (3) (7) (11) (13) (37), so a(6) = 5.
MATHEMATICA
Table[PrimeOmega[(10^n - 1)/9], {n, 60}] (* Michael De Vlieger, Apr 29 2015 *)
PROG
(PARI) a(n)=bigomega(10^n\9) \\ Charles R Greathouse IV, Apr 29 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved