2473929

Appears in sequences

• Odd numbers n not congruent to 5 mod 6 such that for all k >= 1 the numbers n*4^k + 1 are composite.at n=20A251057
• Odd numbers n divisible by 3 such that for all k >= 1 the numbers n*4^k + 1 are composite.at n=9A256002
• a(n) = (conjectured) smallest positive integer k which is neither of the form p + n^x nor of the form p - n^x with x >= 0 and p prime, where gcd(k, n) = 1 and gcd(k^2-1, n-1) = 1.at n=2A283619