a(n) is the smallest number k > 1 such that, in the interval 1..k, there are as many integers that have exactly 2n divisors as there are primes (or -1 if no such number exists).
A356136
a(n) is the smallest number k > 1 such that, in the interval 1..k, there are as many integers that have exactly 2n divisors as there are primes (or -1 if no such number exists).
Terms
- a(0) =2a(1) =27a(2) =-1a(3) =665a(4) =-1a(5) =57675a(6) =-1a(7) =57230a(8) =-1
External references
- oeis: A356136