20753

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 55.at n=25A020394
• Denominators of continued fraction convergents to sqrt(721).at n=13A042389
• a(1) = 2; a(n) is the smallest prime > a(n-1) such that a(n) + a(n-1) is a square.at n=20A062064
• Primes which can be expressed as sum of distinct powers of 4.at n=28A077718
• Primes which are the sum of three positive 4th powers.at n=29A085318
• Series expansion of Farey rational polynomial based on A112627.at n=7A113946
• Primes p of the form a^4+b^4+c^4 with a,b,c>=1 such that a^2+b^2+c^2 is another prime < p.at n=22A126117
• Prime numbers that are the sum of three distinct positive fourth powers.at n=17A126657
• Primes p such that q = p+d (with d >= 6) is the next prime and both p and q are Sophie Germain primes.at n=34A128825
• Primes p such that p - 6^2, p - 6, p + 6 and p + 6^2 are also primes.at n=38A141279
• Primes congruent to 44 mod 59.at n=39A142771
• Lexicographically earliest permutation of the primes such that successive absolute differences yield a permutation of all nonprime numbers.at n=29A203985
• Primes of the form k^2 + 17.at n=8A228244
• Starting with a(1) = 3, a(2) = 5, a(n+1) is the smallest prime number greater than the previous term a(n) such that there exists k satisfying 1<=k<n, a(n+1) = 2*a(n) - a(k).at n=23A238137
• Number of semiprimes with n digits.at n=4A242134
• Number of (n+2) X (3+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 2 3 4 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 2 3 4 6 or 7.at n=5A252162
• Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 2 3 4 6 or 7.at n=2A252165
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 2 3 4 6 or 7.at n=30A252167
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 2 3 4 6 or 7.at n=33A252167
• Sophie Germain primes p such that p+6 and p-6 are primes.at n=23A278869