21727

Properties

Appears in sequences

• Numbers k such that 15*2^k - 1 is prime.at n=31A002237
• Start with n, apply k->2k+1 until reach new record prime; sequence gives number of steps needed.at n=14A051918
• Primes p such that x^36 = 2 has no solution mod p, but x^12 = 2 has a solution mod p.at n=28A059668
• Prime numbers p for which the quintic polynomial x^5 - x - 1 modulo p completely factors into linear polynomials.at n=15A135844
• Prime numbers p not of the form 10*k+1 for which the quintic polynomial x^5-x-1 modulus p is factorizable into five binomials.at n=11A135845
• Mother primes of order 8.at n=36A136067
• Primes congruent to 15 mod 59.at n=39A142742
• Primes p such that p+p^2+p^3-+2 are also prime.at n=35A154821
• Primes p such that 4*p and 6*p are each the sum of two consecutive primes.at n=31A164133
• Primes p with property that there exists a number d>0 such that numbers p-k*d, k=1...7, are seven primes.at n=27A216590
• a(n) = prime(prime(n^2)).at n=18A217623
• 2*n^3 - 313*n^2 + 6823*n - 13633.at n=17A218456
• Primes p with pi(p) and pi(p^2) both prime, where pi(.) is given by A000720.at n=30A237659
• Primes p such that p = the cumulative sum of the digit-sum in base 15 of the digit-product in base 4 of each prime < p.at n=9A242589
• Primes having only {1, 2, 7} as digits.at n=42A260889
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + 2*b(n-1) + 2*b(n-2), where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A294560
• Primes p such that the sum of cubes of the 4 consecutive primes starting with p is twice a prime.at n=23A368637
• Prime numbersat n=2437