a(n) = phi(9^n-1), where phi is Euler's totient function (A000010).
A366663
a(n) = phi(9^n-1), where phi is Euler's totient function (A000010).
Terms
- a(0) =4a(1) =32a(2) =288a(3) =2560a(4) =26400a(5) =165888a(6) =2384928a(7) =15728640a(8) =141087744a(9) =1246080000a(10) =14758128000a(11) =85996339200
External references
- oeis: A366663