
2, 3, 4, 4, 4, 7, 4, 6, 6, 6, 4, 9, 5, 6, 8, 8, 4, 11, 3, 9, 9, 9, 3, 12, 7, 8, 9, 10, 7, 15, 5, 13, 8, 8, 9, 14, 5, 5, 8, 13, 6, 17, 6, 13, 12, 8, 4, 15, 6, 12, 10, 11, 6, 16, 10, 14, 8, 10, 4, 22, 9, 7, 16, 17, 9, 17, 5, 12, 8, 14, 4, 20, 5, 9, 14, 8, 10, 18
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Ray Chandler, Table of n, a(n) for n = 1..322
Makoto Kamada, Factorizations of 11...11 (Repunit).
S. S. Wagstaff, Jr., Main Tables from the Cunningham Project.
S. S. Wagstaff, Jr., The Cunningham Project


FORMULA

Mobius transform of A085035  T. D. Noe, Jun 19 2003
a(n) = Omega(10^n 1) = Omega(R_n) + 2 = A046053(n) + 2 {where Omega(n) = A001222(n) and R_n = (10^n  1)/9 = A002275(n)}.  Lekraj Beedassy, Jun 09 2006
a(n) = A001222(A002283(n)).  Ray Chandler, Apr 22 2017


MATHEMATICA

PrimeOmega[10^Range[70]1] (* Jayanta Basu, May 29 2013 *)


PROG

(PARI) a(n)=bigomega(10^n1) \\ Charles R Greathouse IV, Sep 14 2015


CROSSREFS

Cf. A001222, A002283, A057952A057958, A046051, A046053, A085035.
Sequence in context: A206925 A114212 A108355 * A076410 A211509 A305594
Adjacent sequences: A057948 A057949 A057950 * A057952 A057953 A057954


KEYWORD

nonn


AUTHOR

Patrick De Geest, Nov 15 2000


EXTENSIONS

Erroneous bfile replaced by Ray Chandler, Apr 26 2017


STATUS

approved

