13574218751domain: NAppears in sequencesSmallest number m > 1 such that m^2 == 1 (mod 10^n).at n=10A181539(2*16^(5^n) + (10^n)/2 - 1) mod 10^n: a sequence of trimorphic numbers ending (for n > 1) in 1.at n=10A224476