256999

Appears in sequences

• Strong pseudoprimes to base 2.at n=23A001262
• Divisors of 2^29 - 1.at n=4A003537
• Numbers n such that game of n X n Button Madness need have no solution; this lists only the primitive elements of the set.at n=23A007802
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 77 ones.at n=17A031845
• Smallest base-2 Fermat pseudoprime x that has ord(2,x) = n, or 0 if one does not exist.at n=28A086250
• Overpseudoprimes to base 2: composite k such that k = A137576((k-1)/2).at n=12A141232
• Pseudoprimes to base 2 of the form 4k+3.at n=12A177884
• Composite numbers k == 3 (mod 4) such that (1 + i)^k == 1 - i (mod k), where i = sqrt(-1).at n=3A270697
• Numbers k > 1 such that 2^k == 2 (mod k) and gcd(k, 3^k - 3) = 1.at n=9A300762
• Numbers k such that 2^(k-1) == 1 (mod k) and lpf(k)-1 does not divide k-1.at n=15A316906
• Numbers k such that 2^(k-1) == 1 (mod k) and p-1 does not divide k-1 for every prime p dividing k.at n=13A316907
• Base-2 Fermat pseudoprimes k such that the multiplicative order of 2 modulo k is odd.at n=7A367230
• 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=15A367319