374464040689domain: NAppears in sequencesCarmichael numbers of the form (6*k+1)*(12*k+1)*(18*k+1) which are the product of four prime numbers.at n=7A221742Carmichael numbers of the form (6*k + 1)*(12*k + 1)*(18*k + 1), where only two of the three numbers 6*k + 1, 12*k + 1, 18*k + 1 are prime.at n=16A242980