530881

Appears in sequences

• Carmichael numbers: composite numbers k such that a^(k-1) == 1 (mod k) for every a coprime to k.at n=33A002997
• Absolute Euler pseudoprimes: odd composite numbers n such that a^((n-1)/2) == +-1 (mod n) for every a coprime to n.at n=11A033181
• Pseudoprimes to bases 2 and 7.at n=27A083733
• Pseudoprimes to bases 2,5 and 7.at n=15A083736
• Pseudoprimes to bases 2, 3 and 5.at n=26A083737
• Pseudoprimes to bases 2,3 and 7.at n=22A083738
• Pseudoprimes to bases 2, 3, 5 and 7.at n=14A083739
• Pseudoprimes to bases 3,5 and 7.at n=16A083740
• 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=22A087788
• Records in A098650.at n=16A098652
• Nonprime numbers k such that k divides 3^((k+1)/2) - 2^((k+1)/2) - 1.at n=33A130062
• a(n) is the largest Carmichael number of the form prime(n)*prime(n')*prime(n") with n < n' < n", or 0 if no such number exists.at n=5A141706
• Intersection of A001567 and A212502.at n=19A212601
• Fermat pseudoprimes to base 2 of the form (n^2 + 2*n)/3.at n=16A216170
• Odd octagonal numbers indexed by triangular numbers.at n=20A243201
• Carmichael numbers k such that the odd part of k-1 is squarefree.at n=7A263403
• Carmichael numbers (A002997) that are the sum of two squares.at n=13A265237
• The largest 3-Carmichael number that is divisible by the n-th odd prime.at n=4A290485
• Fermat pseudoprimes to base 2 that are octagonal.at n=16A321868
• Composite numbers k such that p^(k-1) == 1 (mod k) for every prime p strongly prime to k.at n=35A323214