Nonprimes n such that n+cototient(n) is a power of 2.

Terms

a(0) =1a(1) =10a(2) =20a(3) =40a(4) =80a(5) =160a(6) =320a(7) =322a(8) =640a(9) =644a(10) =1280a(11) =1288a(12) =2560a(13) =2576a(14) =5120a(15) =5152a(16) =10240a(17) =10304a(18) =20480a(19) =20608a(20) =40960a(21) =41216a(22) =81920a(23) =82432a(24) =163840a(25) =164864a(26) =327680a(27) =329728a(28) =333634a(29) =655360