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A177892 The number of distinct prime factors in Lucas-Lehmer number A003010(n). 1
1, 2, 2, 3, 2, 3, 6, 3, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(9)>3 and 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..8.

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^2-2, print1(omega(a)", "))  \\ M. F. Hasler, Dec 14 2010

CROSSREFS

Cf. A000040, 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

STATUS

approved

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Last modified October 17 06:08 EDT 2019. Contains 328106 sequences. (Running on oeis4.)