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 A340189 #7 Dec 31 2020 15:34:59 %S A340189 2,1,1,4,1,9,1,8,11,17,1,11,1,25,27,16,1,13,1,17,41,41,1,24,37,49,25, %T A340189 21,1,1,1,32,69,65,79,40,1,73,83,40,1,-7,1,35,21,89,1,48,79,17,111,39, %U A340189 1,61,131,60,125,113,1,83,1,121,27,64,145,-27,1,53,153,-49,1,71,1,145,23,57,193,-31,1,80,83,161,1,131 %N A340189 a(n) = n + A340187(n). %H A340189 Antti Karttunen, <a href="/A340189/b340189.txt">Table of n, a(n) for n = 1..8191</a> %H A340189 Antti Karttunen, <a href="/A340189/a340189.txt">Data supplement: n, a(n) computed for n = 1..65537</a> %F A340189 a(n) = n + A340187(n). %F A340189 a(n) = A340188(n) + A318828(n). %o A340189 (PARI) %o A340189 up_to = 65537; %o A340189 A063994(n) = { my(f=factor(n)); prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); }; %o A340189 DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(d<n, v[n/d]*u[d], 0))); (u) }; \\ Compute the Dirichlet inverse of the sequence given in input vector v. %o A340189 v340187 = DirInverse(vector(up_to, n, A063994(n))); %o A340189 A340187(n) = v340187[n]; %o A340189 A340189(n) = (n+A340187(n)); %Y A340189 Cf. A063994, A318828, A340187, A340188. %Y A340189 Cf. also A318833. %K A340189 sign %O A340189 1,1 %A A340189 _Antti Karttunen_, Dec 31 2020