A177892 - OEIS

A177892

The number of distinct prime factors in Lucas-Lehmer number A003010(n).

1, 2, 2, 3, 2, 3, 6, 3, 5, 5

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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

FORMULA

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

KEYWORD

nonn,hard,more

AUTHOR

EXTENSIONS

a(9) from Wang Runsen, Oct 26 2020

STATUS

approved