1193221

Appears in sequences

• Pseudoprimes to bases 2,5 and 7.at n=26A083736
• Pseudoprimes to bases 2, 3, 5 and 7.at n=21A083739
• Pseudoprimes to bases 3,5 and 7.at n=24A083740
• 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=25A087788
• Carmichael numbers that are not == 1 mod 24.at n=16A097130
• Records in A098650.at n=21A098652
• Carmichael numbers divisible by 31.at n=7A182151
• Carmichael numbers that have only prime divisors of the form 10k+1.at n=4A212843
• Composite numbers k such that k divides Fibonacci(k+1) or Fibonacci(k-1) and 2^(k-1) == 1 (mod k).at n=17A214434
• Fermat pseudoprimes to base 2 of the form (n^2 + 2*n)/3.at n=24A216170
• Carmichael numbers (A002997) that are not absolute Euler pseudoprimes (A033181).at n=31A262043
• Composite numbers n such that gcd(phi(n), n-1) = lambda(n), where lambda(n) = A002322(n).at n=22A264012
• Carmichael numbers that are the average of two consecutive primes.at n=3A265669
• Sarrus numbers (A001567) that are the average of two consecutive primes.at n=15A265684
• Irregular triangle read by rows in which row n contains the first Carmichael number equal to m mod n where m is coprime to n, 0 <= m < n, ordered by m.at n=38A278338
• Fermat pseudoprimes to base 2 that are octagonal.at n=24A321868
• Primary Carmichael numbers.at n=10A324316
• Terms of A324315 (squarefree integers m > 1 such that if prime p divides m, then the sum of the base p digits of m is at least p) that are also octagonal numbers (A000567) with index equal to their largest prime factor.at n=27A324320
• Numbers that are both Fermat pseudoprimes to base 2 (A001567) and Bruckman-Lucas pseudoprimes (A005845).at n=10A329240
• Carmichael numbers k for which A053575(k) [the odd part of phi] does not divide k-1.at n=37A340092