a(n) = smallest k where (10^k+1)=0 mod prime(n)^2, or 0 if no such k exists.

Terms

a(0) =0a(1) =0a(2) =0a(3) =21a(4) =11a(5) =39a(6) =136a(7) =171a(8) =253a(9) =406a(10) =0a(11) =0a(12) =0a(13) =0a(14) =1081a(15) =0a(16) =1711a(17) =1830a(18) =0a(19) =0a(20) =292a(21) =0a(22) =0a(23) =1958a(24) =4656a(25) =202a(26) =1751a(27) =0a(28) =5886a(29) =6328