43889

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 16.at n=25A031604
• Denominators of continued fraction convergents to sqrt(689).at n=4A042325
• Smaller of twin primes whose middle term is a multiple of A002110(5)=2310.at n=5A060231
• Prime(prime(n)) when prime(prime(n)) and n are twin primes.at n=24A087394
• Primes p of the form k*(k + 1) - 1 such that p and p + 2 are twin primes.at n=27A088486
• Primes equal to a sum of primes with differences congruent to (2,4) mod 6.at n=24A104160
• Highly cototient numbers that are prime, or intersection of A000040 and A100827.at n=43A105440
• Triangle T(n, k) = binomial(n, k)^2 - binomial(n, k) - 1, read by rows.at n=59A144403
• Triangle T(n, k) = binomial(n, k)^2 - binomial(n, k) - 1, read by rows.at n=61A144403
• Primes of the form (p^2-1)/4-p where p are also primes.at n=31A165557
• Generalized Markoff numbers: largest of 7-tuple of positive numbers a, b, c, d, e, f, g satisfying the Markoff(7) equation a^2+b^2+c^2+d^2+e^2+f^2+g^2 = 5abcdefg.at n=24A227212
• Primes p such that p+2, p*(p+1)/2-2 and p*(p+1)/2+2 are also primes.at n=18A349336
• Prime numbers of the form 3p+8 where p, p+2 and p+6 are prime numbers.at n=23A376013
• Prime numbersat n=4567