53711113

Appears in sequences

• Carmichael numbers which are also base-2 strong pseudoprimes.at n=16A063847
• Carmichael numbers n such that n-1 is not a practical number.at n=12A265827
• Imprimitive Carmichael numbers: Carmichael numbers m such that if m = p_1 * p_2 * ... *p_k is the prime factorization of m then g(m) = gcd(p_1 - 1, ..., p_k - 1) > sqrt(lambda(m)), where lambda is the Carmichael lambda function (A002322).at n=17A328935
• Carmichael numbers (A002997) that are not minimal in their family.at n=8A335584
• Squarefree base-2 Fermat pseudoprimes divisible by a Wieferich prime.at n=5A353221
• Carmichael numbers ending in 3.at n=16A355309
• 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=27A380979