17236801

Appears in sequences

• Carmichael numbers that have only prime divisors of the form 10k+1.at n=20A212843
• a(1) = 561; a(n+1) = smallest Fermat pseudoprime to all natural bases up to lpf(a(n)).at n=11A300629
• Primary Carmichael numbers.at n=27A324316
• Carmichael numbers k for which the 2-adic valuation of phi(k) does not exceed the 2-adic valuation of k-1.at n=10A339818
• Records in A083876.at n=11A348258
• Least Euler pseudoprime to base 2 through base prime(n).at n=29A354694
• Least Euler pseudoprime to base 2 through base prime(n).at n=30A354694
• The lesser of twin Carmichael numbers: a pair of consecutive Carmichael numbers (A002997) without a non-prime-power weak Carmichael number (A087442) between them.at n=20A365022
• Carmichael numbers k such that k-1 is a Novak-Carmichael number.at n=23A375322
• 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=22A380979