A366707 - OEIS

%I #9 Jan 04 2024 13:25:02

%S 1,2,2,4,2,5,3,6,4,4,3,8,3,6,6,9,3,9,2,7,5,5,4,12,4,7,6,10,5,13,5,11,

%T 7,6,9,14,3,6,7,13,4,13,5,11,12,8,3,18,5,10,6,12,7,16,7,13,7,8,4,18,4,

%U 8,8,13,8,16,5,10,7,14,4,21,3,7,11,11,10,17,4

%N Number of distinct prime divisors of 12^n - 1.

%H Max Alekseyev, <a href="/A366707/b366707.txt">Table of n, a(n) for n = 1..310</a>

%F a(n) = omega(12^n-1) = A001221(A024140(n)).

%o (PARI) for(n = 1, 100, print1(omega(12^n - 1), ", "))

%Y Cf. A024140, A001221, A046800, A133801, A102347, A250288, A252170, A366708, A366709, A366681.

%K nonn

%O 1,2

%A _Sean A. Irvine_, Oct 17 2023