294409

Appears in sequences

• Carmichael numbers: composite numbers k such that a^(k-1) == 1 (mod k) for every a coprime to k.at n=24A002997
• a(n) = (n+1)*(2*n+1)*(3*n+1).at n=36A011199
• Carmichael numbers of the form (6*k+1)*(12*k+1)*(18*k+1), where 6*k+1, 12*k+1 and 18*k+1 are all primes.at n=1A033502
• Zeisel numbers.at n=18A051015
• Numbers k such that phi(k) is a perfect 7th power.at n=32A078167
• Pseudoprimes to bases 2 and 5.at n=25A083732
• Pseudoprimes to bases 2 and 7.at n=18A083733
• Pseudoprimes to bases 3 and 5.at n=24A083734
• Pseudoprimes to bases 3 and 7.at n=23A083735
• Pseudoprimes to bases 2,5 and 7.at n=7A083736
• Pseudoprimes to bases 2, 3 and 5.at n=18A083737
• Pseudoprimes to bases 2,3 and 7.at n=13A083738
• Pseudoprimes to bases 2, 3, 5 and 7.at n=6A083739
• Pseudoprimes to bases 3,5 and 7.at n=8A083740
• 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=15A087788
• Records in A098650.at n=10A098652
• Devaraj numbers: squarefree r-prime-factor (r>1) integers N=p1*...*pr such that phi(N)=(p1-1)*...*(pr-1) divides gcd(p1-1,...,pr-1)^2*(N-1)^(r-2).at n=27A104016
• Nonprime numbers k such that k divides 3^((k+1)/2) - 2^((k+1)/2) - 1.at n=26A130062
• 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=10A135720
• 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=11A141705