%I
%S 5,3,20,2,6,142,183,66,294,88,34,387
%N Smallest base b > 1 such that the smallest baseb Wieferich prime p (i.e., prime p satisfying b^(p1) == 1 mod (p^2)) lies between 10^n and 10^(n+1).
%C In other words, the smallest base b where the smallest baseb Wieferich prime has exactly n+1 digits; i.e., a(n) is the smallest b > 1 such that A055642(A039951(b)) = n+1.
%H R. Fischer, <a href="http://www.fermatquotient.com/FermatQuotienten/FermQ_Sorg.txt">Thema: Fermatquotient B^(P1) == 1 (mod P^2)</a>
%o (PARI) for(n=0, 20, b=2; goodwief=0; while(goodwief==0, badwief=0; forprime(p=1, 10^n, if(Mod(b, p^2)^(p1)==1, badwief++; break({1}))); if(badwief==0, forprime(p=10^n, 10^(n+1), if(Mod(b, p^2)^(p1)==1, print1(b, ", "); goodwief++; break({1})))); b++))
%Y Cf. A039951.
%K nonn,hard,more
%O 0,1
%A _Felix FrÃ¶hlich_, Apr 02 2015
