OFFSET
0,3
COMMENTS
a(n)=1 for n=0,1,5,9,287,8273, see A109076.
EXAMPLE
a(0)=1 because 11^0+2=3(prime),
a(1)=1 because 11^1+2=13(prime),
a(2)=2 because 11^2+2=123=3*41(semiprime),
a(3)=2 because 11^3+2=123=31*43(semiprime),
a(4)=3 because 11^4+2=14643=3^2*1627(3 prime factors).
MATHEMATICA
Table[ PrimeOmega[11^n + 2] , {n, 0, 25}] (* G. C. Greubel, Oct 23 2016 *)
PROG
(PARI) a(n) = bigomega(11^n+2); \\ Michel Marcus, Oct 13 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Mar 03 2008
STATUS
approved