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 A085028 #13 May 22 2022 19:57:06
%S A085028 1,2,1,2,2,1,1,2,1,1,2,1,1,1,1,3,2,2,2,2,1,2,2,1,2,1,3,2,3,2,3,2,1,3,
%T A085028 2,1,2,2,4,1,3,3,2,2,3,1,4,3,5,2,2,2,3,2,3,2,3,3,2,1,2,2,1,2,3,2,3,2,
%U A085028 2,1,1,1,4,3,3,2,3,4,3,2,3,2,4,2,2,1,3,3,3,2,2,2,2,3,2,2,3,2,2,4
%N A085028 Number of prime factors of cyclotomic(n,3), which is A019321(n), the value of the n-th cyclotomic polynomial evaluated at x=3.
%C A085028 The Mobius transform of this sequence yields A057958, number of prime factors of 3^n-1.
%D A085028 See references at A085021
%H A085028 Max Alekseyev, <a href="/A085028/b085028.txt">Table of n, a(n) for n = 1..690</a>
%t A085028 Table[Plus@@Transpose[FactorInteger[Cyclotomic[n, 3]]][[2]], {n, 1, 100}]
%Y A085028 omega(Phi(n,x)): A085021 (x=2), this sequence (x=3), A085029 (x=4), A085030 (x=5), A085031 (x=6), A085032 (x=7), A085033 (x=8), A085034 (x=9), A085035 (x=10).
%Y A085028 Cf. A019321, A057958, A059885, A143663, A218356, A074477.
%K A085028 nonn
%O A085028 1,2
%A A085028 _T. D. Noe_, Jun 19 2003