220901

Properties

Appears in sequences

• Primes p such that all prime factors of p-1 have exponent 2.at n=23A089195
• Lower twin primes p1 such that p1-1 is a square.at n=18A145824
• Primes of the form 1+A162143(k).at n=7A164517
• Primes of the form (10p)^2 + 1, where p is also prime.at n=6A179293
• Primes p of form n^2 + 1 such that p+2 and p+6 are also prime.at n=7A200992
• Primes p such that gcd(phi(p-1), sigma(p-1)) = 1 with phi = A000010, sigma = A000203.at n=40A270539
• Length of n-th iterate of the mapping 00->0010, 01->100, 10->000 in A289235.at n=20A289153
• Prime numbersat n=19689