Numbers m such that 2*phi(m) = phi(m+1).

Terms

a(0) =2a(1) =4a(2) =16a(3) =154a(4) =256a(5) =286a(6) =364a(7) =804a(8) =1066a(9) =2146a(10) =3382a(11) =4550a(12) =6106a(13) =7700a(14) =8176a(15) =9268a(16) =11284a(17) =12556a(18) =12970a(19) =16402a(20) =19228a(21) =19276a(22) =20272a(23) =25132a(24) =26404a(25) =27346a(26) =29154a(27) =29574a(28) =35644a(29) =36418