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 A366681 #8 Jan 04 2024 16:05:53 %S A366681 2,3,4,4,3,6,4,5,5,5,4,9,4,6,6,7,3,8,3,7,9,9,5,12,6,8,6,10,4,11,5,9,9, %T A366681 7,7,12,6,8,12,10,9,13,4,12,8,10,5,18,7,10,9,10,6,11,9,15,7,8,5,16,5, %U A366681 10,15,12,7,19,6,12,10,15,7,18,3,9,13,11,8,20 %N A366681 Number of distinct prime divisors of 11^n - 1. %H A366681 Max Alekseyev, <a href="/A366681/b366681.txt">Table of n, a(n) for n = 1..316</a> %F A366681 a(n) = omega(11^n-1) = A001221(A024127(n)). %o A366681 (PARI) for(n = 1, 100, print1(omega(11^n - 1), ", ")) %Y A366681 Cf. A024127, A001221, A274910, A366682, A366683, A366684, A366685. %Y A366681 Cf. A046800, A133801, A102347, A366707. %K A366681 nonn %O A366681 1,1 %A A366681 _Sean A. Irvine_, Oct 16 2023