27431

Properties

Appears in sequences

• Numbers whose least quadratic nonresidue (A020649) is 17.at n=19A025026
• Number of partitions in parts not of the form 13k, 13k+3 or 13k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 5 are greater than 1.at n=45A035951
• Prime number spiral (clockwise, West spoke).at n=27A054570
• Primes with 17 as smallest positive primitive root.at n=26A061329
• n^2-79*n+1601 as n runs through the lucky numbers.at n=40A087867
• Numbers k such that digit sum of 3^k is a power of 3.at n=31A118872
• Indices k such that 13 plus the k-th triangular number is a perfect square.at n=10A154144
• Primes such that applying "reverse and add" twice produces two more primes.at n=13A174402
• Primes of the form k*6^m - 1, where k is a Mersenne prime (A000668) and m >= 0.at n=9A186687
• Primes of the form 4*n^3-5.at n=6A200732
• Primes of the form 10n^3-9.at n=3A201039
• a(n) = -2*a(n-1) + a(n-2) + a(n-3) with a(0)=a(1)=-1, a(2)=1.at n=14A215112
• Fixed points of A275957; numbers n for which A060125(n) = A225901(n).at n=55A275843
• The indices where A354606(n) = 1.at n=37A355606
• Prime numbersat n=2998