a(n) = phi(7^n-1), where phi is Euler's totient function (A000010).
A366635
a(n) = phi(7^n-1), where phi is Euler's totient function (A000010).
Terms
- a(0) =2a(1) =16a(2) =108a(3) =640a(4) =5600a(5) =36288a(6) =264992a(7) =1536000a(8) =12387168a(9) =85120000a(10) =658519752a(11) =3135283200a(12) =32296336800a(13) =216063877120
External references
- oeis: A366635