a(n) = phi(6^n-1)/n, where phi is Euler's totient function (A000010).
A295496
a(n) = phi(6^n-1)/n, where phi is Euler's totient function (A000010).
Terms
- a(0) =4a(1) =12a(2) =56a(3) =216a(4) =1240a(5) =5040a(6) =31992a(7) =139968a(8) =828576a(9) =3720000a(10) =25238048a(11) =104509440a(12) =803499840a(13) =3687014016a(14) =24373440000a(15) =110630707200a(16) =790546192128
External references
- oeis: A295496