|
| |
|
|
A177892
|
|
The number of distinct prime factors in Lucas-Lehmer 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^2-2, 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
|
| |
|
|
