Least k>1 such that the Euler totient function of powers k^e, 1 <= e <= n, are divisible by the number their divisors, d(k^e).
A272857
Least k>1 such that the Euler totient function of powers k^e, 1 <= e <= n, are divisible by the number their divisors, d(k^e).
Terms
- a(0) =3a(1) =3a(2) =13a(3) =61a(4) =61a(5) =421a(6) =2521a(7) =2521a(8) =2521a(9) =55441a(10) =55441a(11) =4324321a(12) =4324321a(13) =4324321a(14) =4324321a(15) =85765681a(16) =85765681a(17) =232792561a(18) =232792561a(19) =232792561a(20) =232792561
External references
- oeis: A272857