n+phi(n)+phi(phi(n)) is a cube.

Terms

a(0) =15a(1) =40a(2) =293a(3) =320a(4) =723a(5) =967a(6) =1057a(7) =1173a(8) =2560a(9) =4104a(10) =5287a(11) =6680a(12) =10312a(13) =14537a(14) =16472a(15) =18040a(16) =18785a(17) =19288a(18) =19521a(19) =20480a(20) =22297a(21) =27129a(22) =32832a(23) =32902a(24) =33929a(25) =36563a(26) =38507a(27) =53352a(28) =53440a(29) =80200