3720000

Appears in sequences

• a(n) = phi(6^n-1)/n, where phi is Euler's totient function (A000010).at n=9A295496
• Consider primitive pairs of integers (b, c) with b > 0 such that x^5 + b*x + c = 0 is irreducible and solvable by radicals: sequence gives values of c.at n=31A371554