27259

Properties

Appears in sequences

• Smallest prime p such that the product of q/(q-1) over the primes from prime(n) to p is greater than 2.at n=36A001275
• Fibonacci sequence beginning 1, 27.at n=16A022397
• Numbers k such that k^2+k+7 is a palindrome.at n=12A027722
• Primes p whose period of reciprocal equals (p-1)/7.at n=22A056212
• Average of four successive primes squared, (prime(n)^2 + prime(n+1)^2 + prime(n+2)^2 + prime(n+3)^2)/4, n>=2.at n=35A075894
• Primes p such that the sum of the digits of p is not prime, but the sum of each digit raised to the 4th power is prime.at n=23A091368
• Prime numbers that are 2 less than a prime-indexed odd triangular number or 1 more than a prime-indexed even triangular number.at n=30A096333
• Primes p equal to the sum of two successive sexy primes - 1 such that p - 6 is also prime.at n=32A104047
• Number of monocyclic skeletons with n carbon atoms and a ring size of 9.at n=9A121156
• Number of cubefree integers not exceeding 2^n.at n=15A160113
• Primes of the form p + (p^2 - 1)/8, where p is also prime.at n=22A165352
• Primes of the form 8*k^2 + 6*k - 1 for positive k.at n=30A187677
• Primes which are the arithmetic mean of the squares of four consecutive primes.at n=8A234364
• Primes p such that 2*p+1 is divisible by the sum of digits of p+1.at n=44A267542
• G.f. A(x) satisfies: A(x) = 1 + Sum_{k>=1} mu(k)^2*x^k*A(x)^k/(1 - x^k*A(x)^k)^2, where mu() is the Möbius function (A008683).at n=8A307488
• Primes p such that (p^128 + 1)/2 is prime.at n=18A341230
• Primes of the form T(p) - 2 where T(p) is the triangular number (A000217) with prime index p in A357218.at n=15A357219
• Prime numbersat n=2984