Squarefree numbers k such that phi(k) = phi(k+1).

Terms

a(0) =1a(1) =3a(2) =15a(3) =194a(4) =255a(5) =2834a(6) =3255a(7) =3705a(8) =5186a(9) =5187a(10) =11715a(11) =22935a(12) =25545a(13) =49215a(14) =49335a(15) =65535a(16) =214334a(17) =256274a(18) =388245a(19) =525986a(20) =568815a(21) =589407a(22) =840255a(23) =936494a(24) =1259642a(25) =1574727a(26) =1659585a(27) =1759874a(28) =1788254a(29) =2123583