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 A097946 #7 Jul 19 2017 20:07:57
%S A097946 2,-3,0,0,0,4,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,-2,0,0,0,
%T A097946 0,0,0,0,0,0,0,0,-4,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,-2,
%U A097946 0,0,0,-2,0,0,0,0,0,0,0,-2,0,0,0,2,0,0,0,0,0,0,0,0,0,0
%N A097946 a(n) = A008683(n)*A014197(n) where A008683 is the Moebius (or Mobius) function mu(n) and A014197 is the number of numbers m with Euler phi(m) = n.
%C A097946 For n < 93 and a(n) not 0, n = p - 1 where p is prime and therefore in A077064 (Squarefree numbers of form prime - 1.)
%H A097946 Antti Karttunen, <a href="/A097946/b097946.txt">Table of n, a(n) for n = 1..10000</a>
%o A097946 (PARI)
%o A097946 A014197(n, m=1) = { n==1 && return(1+(m<2)); my(p, q); sumdiv(n, d, if( d>=m && isprime(d+1), sum( i=0, valuation(q=n\d, p=d+1), A014197(q\p^i, p))))} \\ This function from _M. F. Hasler_, Oct 05 2009
%o A097946 A097946(n) = moebius(n)*A014197(n); \\ _Antti Karttunen_, Jul 19 2017
%Y A097946 Cf. A000010, A008683, A014197, A077064, A097945.
%K A097946 sign
%O A097946 1,1
%A A097946 _Gerald McGarvey_, Sep 04 2004