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 A281962 #13 Feb 09 2017 15:38:28 %S A281962 2,3,7,3,25,5,49,3,17,5,13,3,41,7,5,3,13,5,25,3,25,5,53,3,9,9,25,3,29, %T A281962 3,81,3,9,15,5,3,13,5,13,3,33,5,49,3,5,9,25,3,9,3,9,3,81,5,5,3,25,7, %U A281962 49,3,13,9,13,3,13,3 %N A281962 Least k such that k^n - 1 is a totient number (A002202), or 0 if no such k exists. %e A281962 a(5) = 25 because 25^5 - 1 = 5^10 - 1 = 9765624 is a totient number and 25 is the least number with this property. %o A281962 (PARI) a(n) = my(k=1); while(!istotient(k^n-1), k++); k; %Y A281962 Cf. A000010, A002202, A045542, A281909. %K A281962 nonn,more %O A281962 1,1 %A A281962 _Altug Alkan_, Feb 03 2017 %E A281962 a(43)-a(52) from _Ray Chandler_, Feb 08 2017 %E A281962 a(53)-a(66) from _Ray Chandler_, Feb 09 2017