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 A353600 #6 Apr 29 2022 17:30:38 %S A353600 9,10,33,18,73,19,129,82,201,9,289,22,393,199,513,40,649,54,801,244, %T A353600 969,42,1153,443,1353,730,753,41,1801,117,2049,604,2313,1126,2593,76, %U A353600 2889,1351,3201,148,3529,75,3873,568,4233,67,4609,1048,5001,2024,1329,406 %N A353600 Second-smallest Wieferich base of n, i.e., second-smallest b > 1 such that b^(n-1) == 1 (mod n^2). %o A353600 (PARI) a(n) = my(i=0); for(b=2, oo, if(Mod(b, n^2)^(n-1)==1, if(i==0, i++, return(b)))) %o A353600 (Python) %o A353600 def b(n, startk=2): %o A353600 k, n2 = startk, n*n %o A353600 while pow(k, n-1, n2) != 1: k += 1 %o A353600 return k %o A353600 def a(n): return b(n, startk=b(n)+1) %o A353600 print([a(n) for n in range(2, 54)]) # _Michael S. Branicky_, Apr 29 2022 %Y A353600 Cf. A039678, A185103, A256517. Column 2 of A353602. %K A353600 nonn %O A353600 2,1 %A A353600 _Felix Fröhlich_, Apr 29 2022