2508013

Appears in sequences

• Least pseudoprime to base 2 through base prime(n).at n=13A083876
• Least pseudoprime to base 2 through base prime(n).at n=14A083876
• 3-Carmichael numbers: Carmichael numbers equal to the product of 3 primes: k = p*q*r, where p < q < r are primes such that a^(k-1) == 1 (mod k) if a is prime to k.at n=30A087788
• Carmichael numbers that are not == 1 mod 24.at n=19A097130
• a(n) is the smallest Carmichael number (A002997) with the n-th prime as its smallest prime divisor, or 0 if no such number exists.at n=14A135720
• a(n) is the smallest Carmichael number (A002997) divisible by the n-th prime, or 0 if no such number exists.at n=20A135721
• a(n) is the least Carmichael number of the form prime(n)*prime(n')*prime(n") with n < n' < n", or 0 if no such number exists.at n=15A141705
• Least Carmichael number that is divisible by the n-th cyclic number A003277(n), or 0 if no such number exists.at n=27A253595
• Composite numbers n such that gcd(phi(n), n-1) = lambda(n), where lambda(n) = A002322(n).at n=24A264012
• The least 3-Carmichael number that is divisible by the n-th odd prime, or 0 if no such number exists.at n=14A290486
• The least 3-Carmichael number that is divisible by the n-th odd prime, or 0 if no such number exists.at n=20A290486
• a(1) = 561; a(n+1) = smallest Fermat pseudoprime to all natural bases up to lpf(a(n)).at n=7A300629
• Let E(n,k) denote the k-th smallest Carmichael number such that there are n distinct Carmichael numbers: {x(1), x(2), ..., x(n)} where x_i < E_(n,k), such that for any integer i: 1 <= i <= n, x(i) is a quadratic residue of E(n,k).at n=7A317247
• Records in A083876.at n=7A348258
• Carmichael numbers whose number of prime factors is prime.at n=32A355039
• Carmichael numbers ending in 3.at n=5A355309
• Composites that cause a witness to be added to a set of Fermat witnesses: a(n) is the smallest composite number that is not guaranteed composite using Fermat's Little Theorem by the witness A380978(i) for any i < n.at n=13A380979