656601

Appears in sequences

• Absolute Euler pseudoprimes: odd composite numbers n such that a^((n-1)/2) == +-1 (mod n) for every a coprime to n.at n=12A033181
• Pseudoprimes k to base 2 such that k-2 and k+2 are primes.at n=4A057942
• Smith numbers which are also base-2 pseudoprimes.at n=7A063844
• Carmichael numbers with exactly 4 prime factors.at n=12A074379
• Pseudoprimes to bases 2,5 and 7.at n=17A083736
• Carmichael numbers C such that C-1 is not a Niven/Harshad number.at n=5A097061
• Carmichael numbers that are not == 1 mod 24.at n=12A097130
• Pseudoquadprimes: p+4 for primes p where p+4 divides p^(p+4) + 4 and p+4 is composite.at n=32A100875
• Carmichael numbers that are not == 1 mod 12. There are 69 Carmichael numbers out to 2*m+1, m=2*10^6 and all but the above 9 are 1 mod 12.at n=5A110889
• Pseudoprimes (base-2) equal to product of 4 primes not necessarily distinct.at n=32A112441
• Sarrus numbers that become prime when two is added.at n=20A137198
• Carmichael numbers with more than 3 prime factors.at n=12A141711
• Composite numbers n with the property that phi(n) divides (n-1)^2.at n=32A173703
• Carmichael numbers divisible by 11.at n=4A182090
• Numbers k such that at least one of k and k+2 is composite, while for every b coprime to k*(k+2), b^(k-1) == 1 (mod k) and b^(k+1) == 1 (mod k+2).at n=15A194231
• Carmichael numbers not congruent to 1 modulo 6.at n=4A205947
• 3*n*(9n + 2)*(18n - 1), where n runs through the odd numbers 1, 3, 5,...at n=5A213071
• Pseudoprimes to a twin prime criterion of Aebi and Cairns.at n=21A224695
• Pseudoprimes n to base 2 such that n-4, n-2 and n+2 are primes.at n=1A228575
• Pseudoprimes n to base 2 such that n-2 and n-4 are primes.at n=5A230488