21277

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 77.at n=26A020416
• Primes p from A031924 such that A052180(primepi(p)) = 13.at n=32A052233
• Primes p such that x^27 = 2 has no solution mod p, but x^9 = 2 has a solution mod p.at n=7A059354
• 10000n+1, 10000n+3, 10000n+7, 10000n+9 are all primes.at n=11A064963
• Primes p such that x^9 = 2 has a solution mod p, but x^(9^2) = 2 has no solution mod p.at n=8A070185
• Prime numbers p such that pi(p) + 2*p is a square.at n=18A104783
• Primes congruent to 49 mod 61.at n=34A142847
• Primes p such that the multiplicative order of 2 modulo p is (p-1)/9.at n=13A152309
• Number of ways to place zero or more nonadjacent 1,0 1,1 2,1 2,2 3,1 3,2 4,2 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155358
• Smallest number m such that A196527(m) = n.at n=45A196528
• Primes having only {1, 2, 7} as digits.at n=41A260889
• Prime numbersat n=2390