42719

Properties

Appears in sequences

• Number of ways to represent n using the binary operator a * b = 2^a + b.at n=18A000630
• Numbers whose least quadratic nonresidue (A020649) is 19.at n=15A025027
• Primes with 19 as smallest positive primitive root.at n=34A061331
• Odd numbers n for which 19 is the smallest i (>= 1) with Jacobi symbol J(i,n) getting either a value 0 or -1.at n=23A112078
• Primes p such that 2*p^4+-9 are also prime.at n=22A174365
• a(n) = (4*n^3-3*n^2+5*n-3)/3.at n=31A177342
• Primes p such that A008472(p-1) = A008472(p+1), where A008472 = sum of distinct primes dividing n.at n=5A203182
• a(n) is a prime number that cannot be the center term of a length 3 arithmetic progression prime group with a common difference whose number of runs in binary expansion is 2.at n=37A231387
• Least prime p such that more than half of all integers are divisible by n distinct primes not greater than p.at n=2A284411
• a(0) = a(1) = 1, a(n) is the smallest positive integer m >= a(n-1) + a(n-2) such that gcd(a(k),m) = 1 for all 1 < k <= n - 1.at n=22A345471
• Prime numbersat n=4467