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 A121519 #6 Sep 25 2021 06:49:28 %S A121519 1,2,4,8,10,12,16,22,24,28,40,52,64,72,82,84,88,112,128,130,132,144, %T A121519 156,172,178,190,192,232,238,250,252,276,280,292,324,358,384,396,400, %U A121519 418,424,430,442,448,480,490,508,520,544,552,592,612,640,652,658,682,712 %N A121519 Number of primitive roots of prime A103203(n). %C A121519 Also records in A008330. %H A121519 Amiram Eldar, <a href="/A121519/b121519.txt">Table of n, a(n) for n = 1..10000</a> %e A121519 Prime A103203(5) = 23 has 10 primitive roots, so a(5) = 10; 23 = prime(9) and A008330(9) = 10 is a record in A008330. %o A121519 (PARI) r=0;for(n=1,230,k=eulerphi(prime(n)-1);if(r<k,r=k;print1(k,","))) %Y A121519 Cf. A008330, A103203. %K A121519 nonn %O A121519 1,2 %A A121519 _Klaus Brockhaus_, Aug 06 2006