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 A349400 #8 Nov 25 2021 20:32:25
%S A349400 1,-2,-4,-2,-3,7,-12,8,6,7,-15,18,-14,41,3,-12,-16,-4,-22,9,63,33,-30,
%T A349400 -49,-26,28,-10,15,-39,-2,-32,6,103,13,30,-69,-19,31,67,-68,-44,-218,
%U A349400 -23,39,36,70,-52,38,88,67,65,52,-55,-21,20,-294,147,69,-66,-52,-31,35,-144,48,16,-240,-37,93,165,-180,-76,78
%N A349400 Dirichlet inverse of EKG-permutation, A064413.
%H A349400 Antti Karttunen, <a href="/A349400/b349400.txt">Table of n, a(n) for n = 1..20000</a>
%H A349400 <a href="/index/Ed#EKG">Index entries for sequences related to EKG sequence</a>
%F A349400 a(1) = 1; a(n) = -Sum_{d|n, d < n} A064413(n/d) * a(d).
%o A349400 (PARI)
%o A349400 v064413 = readvec("b064413_to.txt"); \\ Data prepared with _Chai Wah Wu_'s Dec 08 2014 Python-program given in A064413.
%o A349400 A064413(n) = v064413[n];
%o A349400 memoA349400 = Map();
%o A349400 A349400(n) = if(1==n,1,my(v); if(mapisdefined(memoA349400,n,&v), v, v = -sumdiv(n,d,if(d<n,A064413(n/d)*A349400(d),0)); mapput(memoA349400,n,v); (v)));
%Y A349400 Cf. A064413, A323411, A349614.
%K A349400 sign
%O A349400 1,2
%A A349400 _Antti Karttunen_, Nov 19 2021