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 A051400 #22 Mar 18 2017 22:03:19
%S A051400 1,95,218,219,221,554,586,1357,1389,1393,1403,1405,1418,3227,3233,
%T A051400 3235,3239,3241,3242,3277,3281,3293,3295,8201,8413,8418,8489,8490,
%U A051400 8491,8503,8506,8507,8509,8510,8511,11759,11761,11762,11769,11770,11771,11773
%N A051400 Smallest value of x such that M(x) = n, where M() is Mertens's function A002321.
%H A051400 T. D. Noe, <a href="/A051400/b051400.txt">Table of n, a(n) for n = 1..1000</a>
%o A051400 (PARI) a(n) = {x = 0; while (sum(k=1,x,moebius(k)) != n, x++); x} \\ _Michel Marcus_, Sep 24 2013
%o A051400 (PARI) M(n)=sum(k=1,n,moebius(k));
%o A051400 print1(1,", "); c=M(1); n=2; while(n<10^4,if(M(n)>c,print1(n,", "); c=M(n)); n++) \\ _Derek Orr_, Jun 14 2016
%Y A051400 Cf. A002321, A051401, A051402.
%K A051400 nonn
%O A051400 1,2
%A A051400 _Jud McCranie_