A366620 - OEIS

%I #10 Oct 02 2024 07:14:38

%S 1,2,2,3,2,4,2,4,4,5,3,7,3,5,5,6,5,7,3,8,4,5,5,9,4,7,6,8,2,10,3,9,6,8,

%T 6,13,6,6,6,11,3,9,5,9,10,8,4,13,5,8,9,11,4,11,6,13,7,6,4,19,4,5,10,

%U 12,8,12,3,11,8,16,2,18,5,10,10,9,6,15,4,16,8

%N Number of distinct prime divisors of 6^n - 1.

%H Max Alekseyev, <a href="/A366620/b366620.txt">Table of n, a(n) for n = 1..420</a>

%F a(n) = omega(6^n-1) = A001221(A024062(n)).

%o (PARI) for(n = 1, 100, print1(omega(6^n - 1), ", "))

%Y Cf. A024062, A001221, A057955, A059888, A274907, A366621, A366622, A366623.

%Y Cf. A046800, A133801, A366604, A366611, A366632, A366651, A366660, A102347, A366681, A366707.

%K nonn

%O 1,2

%A _Sean A. Irvine_, Oct 14 2023