5481451

Appears in sequences

• Carmichael numbers C such that C-1 is not a Niven/Harshad number.at n=16A097061
• Carmichael numbers that are not == 1 mod 24.at n=24A097130
• Carmichael numbers that are not == 1 mod 12. There are 69 Carmichael numbers out to 2*m+1, m=2*10^6 and all but the above 9 are 1 mod 12.at n=10A110889
• Poulet numbers of the form (6k+1)*(24k+1).at n=20A182123
• Carmichael numbers divisible by 31.at n=14A182151
• Carmichael numbers congruent to 3 modulo 4.at n=3A185321
• Carmichael numbers that have only prime divisors of the form 10k+1.at n=11A212843
• Strong pseudoprimes to bases 3 and 5.at n=7A215566
• Numbers of the form 4k+3 (A004767) that are Lucas pseudoprimes and Fermat pseudoprimes to base 2 (intersection of A005845 and A001567).at n=2A227905
• Composite numbers n such that gcd(phi(n), n-1) = lambda(n), where lambda(n) = A002322(n).at n=31A264012
• Numbers that are both Fermat pseudoprimes to base 2 (A001567) and Bruckman-Lucas pseudoprimes (A005845).at n=27A329240
• Carmichael numbers all of whose prime factors are congruent to 3 modulo 4.at n=4A329468
• Odd composite numbers k such that A111076(k)^((k-1)/2) == -1 (mod k).at n=2A329538
• Odd composite numbers k for which the number of witnesses for strong pseudoprimality of k equals phi(k)/4, where phi is the Euler totient function (A000010).at n=31A329759
• Odd squarefree composite numbers k such that p-1 divides k-1 and p-1 does not divide (k-1)/2 for every prime p|k.at n=6A329799
• Euler-Fibonacci pseudoprimes: odd composites k such that F(k) == 5^((k-1)/2) == +-1 (mod k), where F(k) = A000045(k), the Fibonacci numbers.at n=21A345753
• Carmichael numbers with exactly 3 prime factors, p*q*r, such that p-1, q-1 and r-1 have an equal 2-adic valuation.at n=6A382791