213613

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 71.at n=5A031659
• Restricted left truncatable (Henry VIII) primes.at n=32A055521
• Left-truncatable primes p with property that prepending any single decimal digit to p does not produce a prime.at n=34A240768
• Primes p such that 2*p^2 - 7, 2*p^2 - 1, and 2*p^2 + 3 are prime.at n=28A356510
• Prime numbersat n=19098