This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A366620 #13 Apr 15 2025 22:20:32 %S A366620 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 A366620 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 A366620 12,8,12,3,11,8,16,2,18,5,10,10,9,6,15,4,16,8 %N A366620 Number of distinct prime divisors of 6^n - 1. %H A366620 Max Alekseyev, <a href="/A366620/b366620.txt">Table of n, a(n) for n = 1..430</a> %F A366620 a(n) = omega(6^n-1) = A001221(A024062(n)). %o A366620 (PARI) for(n = 1, 100, print1(omega(6^n - 1), ", ")) %Y A366620 Cf. A024062, A001221, A057955, A059888, A274907, A366621, A366622, A366623. %Y A366620 Cf. A046800, A133801, A366604, A366611, A366632, A366651, A366660, A102347, A366681, A366707. %K A366620 nonn %O A366620 1,2 %A A366620 _Sean A. Irvine_, Oct 14 2023