26309

Properties

Appears in sequences

• a(n) = [ 1/(2*t(n+1) - t(n) - t(n+2)) ], where t(n) = tan(Pi/2 - 1/n) satisfies n-1 < t(n) < n for all n >= 1.at n=24A024817
• Primes p such that continued fraction of (1+sqrt(p))/2 has period 5 : primes in A146330.at n=40A146350
• Primes q = 4*p+1, where p == 2 (mod 5) is also prime.at n=44A221981
• Primes p such that p*q*r + 6 and p*q*r - 6 are primes where q and r are the next two primes after p.at n=19A240715
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 355", based on the 5-celled von Neumann neighborhood.at n=34A271399
• Balanced primes of order fourteen.at n=4A300365
• Happy Honaker primes.at n=25A343192
• Primes p whose reverse q is a semiprime, and of p+q and its reverse one is a prime and the other is a semiprime.at n=31A350781
• Primes whose position in the Wythoff array is immediately followed by a prime both in the next column and the next row.at n=15A352537
• Prime numbersat n=2891