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 A084167 #13 Mar 09 2020 09:13:32 %S A084167 1,5,17,109,157,317,389,449,709,1201,1237,1249,1429,1621,1801,2341, %T A084167 3001 %N A084167 Numbers k in A002313 such that the count of primitive roots of k (A084168) are also in sequence A002313, where A002313 is the list of primes p having a unique representation as the sum of two squares, p = x^2 + y^2. %e A084167 449 = 20^2 + 7^2 has 192 primitive roots, of which 41 are prime, of which 20 are in A002313. %Y A084167 Cf. A002313, A084168. %K A084167 nonn,fini,full,easy %O A084167 1,2 %A A084167 _Sven Simon_, May 17 2003 %E A084167 Offset changed to 1 by _Jinyuan Wang_, Mar 09 2020 %E A084167 Name edited by _Michel Marcus_, Mar 09 2020