

A177892


The number of distinct prime factors in LucasLehmer number A003010(n).


1




OFFSET

0,2


COMMENTS

a(10)>2: results from www.factordb.com.  R. J. Mathar, Dec 15 2010
a(11)=4, factorization added to www.factordb.com.  Sean A. Irvine, Mar 25 2011


LINKS

Table of n, a(n) for n=0..9.
Dario Alejandro Alpern, Factorization using the Elliptic Curve Method (along with sigma_0, sigma_1 and phi functions)


FORMULA

a(n) = A001221(A003010(n)).


MATHEMATICA

Table[PrimeNu[Ceiling[(2 + Sqrt[3])^(2^n)]], {n, 0, 5}] (* G. C. Greubel, May 16 2017 *)


PROG

(PARI) a=4; until(a=a^22, print1(omega(a)", ")) \\ M. F. Hasler, Dec 14 2010


CROSSREFS

Cf. A001221, A003010, A177876.
Sequence in context: A056160 A106245 A129568 * A236433 A117122 A122828
Adjacent sequences: A177889 A177890 A177891 * A177893 A177894 A177895


KEYWORD

nonn,hard,more


AUTHOR

G. L. Honaker, Jr., Dec 14 2010


EXTENSIONS

a(9) from Wang Runsen, Oct 26 2020


STATUS

approved



