4188889

Appears in sequences

• Divisors of 2^43 - 1.at n=4A003548
• Least d > 0 such that both Q = M + 2d and R = M + (M^2-1)/(Q-M) are prime, where M = 2^n - 1 = A000225(n), or 0 if there is no such d.at n=43A320875
• Base-2 Fermat pseudoprimes k such that the multiplicative order of 2 modulo k is odd.at n=25A367230
• Base-2 Fermat pseudoprimes k such that (k-1)/ord(2, k) > (m-1)/ord(2, m) for all base-2 Fermat pseudoprimes m < k, where ord(2, k) is the multiplicative order of 2 modulo k.at n=24A367319