Numbers k such that phi(k) = phi(k+1) and simultaneously Product_{d|k} phi(d) = Product_{d|(k+1)} phi(d) where phi(x) = Euler totient function (A000010).
A247174
Numbers k such that phi(k) = phi(k+1) and simultaneously Product_{d|k} phi(d) = Product_{d|(k+1)} phi(d) where phi(x) = Euler totient function (A000010).
Terms
- a(0) =1a(1) =3a(2) =15a(3) =255a(4) =65535a(5) =2200694a(6) =2619705a(7) =6372794a(8) =40588485a(9) =76466985a(10) =81591194a(11) =118018094a(12) =206569605a(13) =470542485a(14) =525644385a(15) =726638834a(16) =791937614a(17) =971122514a(18) =991172805
External references
- oeis: A247174