3146221domain: NAppears in sequencesCarmichael numbers that are not == 1 mod 24.at n=21A097130Carmichael numbers divisible by 31.at n=11A182151Composite numbers n such that gcd(phi(n), n-1) = lambda(n), where lambda(n) = A002322(n).at n=26A264012Carmichael numbers that are the sum of 2 positive cubes.at n=8A379656