340561

Appears in sequences

• Carmichael numbers: composite numbers k such that a^(k-1) == 1 (mod k) for every a coprime to k.at n=27A002997
• Carmichael numbers with exactly 4 prime factors.at n=9A074379
• Pseudoprimes to bases 2 and 5.at n=28A083732
• Pseudoprimes to bases 2 and 7.at n=21A083733
• Pseudoprimes to bases 3 and 5.at n=27A083734
• Pseudoprimes to bases 3 and 7.at n=26A083735
• Pseudoprimes to bases 2,5 and 7.at n=10A083736
• Pseudoprimes to bases 2, 3 and 5.at n=21A083737
• Pseudoprimes to bases 2,3 and 7.at n=16A083738
• Pseudoprimes to bases 2, 3, 5 and 7.at n=9A083739
• Pseudoprimes to bases 3,5 and 7.at n=11A083740
• Records in A098650.at n=12A098652
• Devaraj numbers: squarefree r-prime-factor (r>1) integers N=p1*...*pr such that phi(N)=(p1-1)*...*(pr-1) divides gcd(p1-1,...,pr-1)^2*(N-1)^(r-2).at n=30A104016
• Pseudoprimes (base-2) equal to product of 4 primes not necessarily distinct.at n=23A112441
• Carmichael numbers with more than 3 prime factors.at n=9A141711
• Composite numbers n with the property that phi(n) divides (n-1)^2.at n=27A173703
• Carmichael numbers of the form C = (30n-7)*(90n-23)*(300n-79).at n=0A182132
• Carmichael numbers of the form C = 23*67*(66n+23).at n=0A182515
• Carmichael numbers (A002997) that are not absolute Euler pseudoprimes (A033181).at n=19A262043
• Carmichael numbers k such that Euler totient function of k (phi(k)) is a perfect square.at n=5A272798