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 A305806 #6 Jun 13 2018 23:10:56
%S A305806 1,0,0,1,0,1,0,0,2,3,0,-1,0,1,2,2,0,-2,0,-3,2,3,0,0,2,3,2,3,0,-5,0,-2,
%T A305806 2,3,4,4,0,1,2,2,0,-3,0,-3,-2,3,0,-2,2,-2,4,1,0,-2,2,-2,4,5,0,3,0,1,
%U A305806 -2,2,4,-1,0,-3,2,-5,0,-4,0,1,-2,1,4,-1,0,-4,-2,3,0,-3,2,3,4,4,0,2,2,-1,4,5,6,8,0,-2,-2,2,0,-7,0,-4,-6
%N A305806 Möbius transform of A175851.
%H A305806 Antti Karttunen, <a href="/A305806/b305806.txt">Table of n, a(n) for n = 1..65537</a>
%F A305806 a(n) = Sum_{d|n} A008683(n/d)*A175851(d).
%o A305806 (PARI)
%o A305806 A175851(n) = if(1==n,n,1 + n - precprime(n));
%o A305806 A305806(n) = sumdiv(n,d,moebius(n/d)*A175851(d));
%Y A305806 Cf. A008683, A175851, A305791, A305805.
%K A305806 sign
%O A305806 1,9
%A A305806 _Antti Karttunen_, Jun 13 2018