540541

Properties

Appears in sequences

• Smallest number that is centered polygonal in exactly n ways.at n=26A063773
• Primes of the form k# + (k+1)# +- 1, where k# = A002110(k) = primorial(k).at n=8A125191
• Primes formed by concatenating k with k+1, where k+1 is a prime.at n=25A134428
• The greater of twin primes p2 such that 2*p1 + p2 is a prime number (A174913) and also the lesser of other twin primes in A174913.at n=15A242773
• a(n) = the least integer that is centered polygonal in exactly n ways.at n=25A279830
• Numbers k such that psi(phi(k))/k > psi(phi(m))/m for all m < k, where phi is Euler's totient function (A000010) and psi is the Dedekind psi function (A001615).at n=33A293712
• Prime numbersat n=44613