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 A181587 #17 Nov 09 2022 10:06:33 %S A181587 1,0,-1,0,-2,0,-2,0,-2,0,-2,0,-3,0,-1,0,-2,0,-3,0,-2,0,-2,0,-2,0,-1,0, %T A181587 -2,0,-4,0,-3,0,-1,0,-2,0,0,0,-1,0,-3,0,-3,0,-3,0,-3,0,-2,0,-3,0,-2,0, %U A181587 -1,0,-1,0,-2,0,-1,0,0,0,-2,0,-1,0,-3,0,-4,0,-3,0,-2,0,-4,0,-4,0,-4,0,-3,0,-1,0,-2,0,-1,0,0,0,2 %N A181587 If n is even, a(n) = 0, if n is odd, a(n) = A002321(n), where A002321 is Mertens's function. %H A181587 Antti Karttunen, <a href="/A181587/b181587.txt">Table of n, a(n) for n = 1..65537</a> %F A181587 a(n) = A000035(n)*A002321(n). %o A181587 (PARI) A181587(n) = if(n%2, sum(k=1, n, moebius(k)), 0); \\ _Antti Karttunen_, Sep 30 2018 %Y A181587 Cf. A000035, A002321. %K A181587 sign,look %O A181587 1,5 %A A181587 _Mats Granvik_, Oct 31 2010 %E A181587 Definition corrected and more terms by _Antti Karttunen_, Sep 30 2018 %E A181587 Incorrect g.f. removed by _Georg Fischer_, Nov 09 2022