81371

Properties

Appears in sequences

• Number of rhyme schemes (see reference for precise definition).at n=6A127021
• Primes p such that each of the numbers p^k for k=1..5 has exactly two 1s in its decimal representation.at n=6A175964
• Primes of the form 13*n^2+3*n+1.at n=37A176783
• Prime numbers containing the digit string 137.at n=34A190307
• Prime p such that p and p+2 are twin primes and p^2+p-1 p^2+p+1 are also twin primes.at n=21A228968
• a(n) = Sum_{k >= 0} floor(n^(2*k+1) / (2*k+1)!).at n=12A309104
• a(n) = Sum_{k >= 0} floor(n^(2*k) / (2*k)!).at n=12A309105
• Prime numbersat n=7963