1425781249domain: NAppears in sequencesSmallest number m > 1 such that m^2 == 1 (mod 10^n).at n=9A181539(2*5^(2^n) + (10^n)/2 - 1) mod 10^n: a sequence of trimorphic numbers ending (for n > 1) in 9.at n=9A224475