

A113913


Number of distinct prime factors of 3^(3^n)+1.


1




OFFSET

0,2


COMMENTS

The term omega(3^(3^6)+1) was obtained with ECM factoring.


LINKS

Table of n, a(n) for n=0..6.


FORMULA

a(n) = A001221(A129290(n)).


MATHEMATICA

Table[PrimeNu[3^(3^n) + 1], {n, 1, 10}] (* G. C. Greubel, May 16 2017 *)


PROG

(PARI) for(x=1, 6, print1( omega(3^(3^x)+1), ", "))


CROSSREFS

Sequence in context: A000694 A164137 A018170 * A002097 A026757 A026385
Adjacent sequences: A113910 A113911 A113912 * A113914 A113915 A113916


KEYWORD

hard,more,nonn


AUTHOR

Jorge Coveiro (jorgecoveiro(AT)yahoo.com), Jan 29 2006


STATUS

approved



