a(n) = phi(2^prime(n) - 1)/prime(n); a(0) = 0 by convention.
A056743
a(n) = phi(2^prime(n) - 1)/prime(n); a(0) = 0 by convention.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =6a(4) =18a(5) =176a(6) =630a(7) =7710a(8) =27594a(9) =356960a(10) =18407808a(11) =69273666a(12) =3697909056a(13) =53630700752a(14) =204064589160
External references
- oeis: A056743