A243306 2^phi(n) - phi(n).

1, 1, 2, 2, 12, 2, 58, 12, 58, 12, 1014, 12, 4084, 58, 248, 248, 65520, 58, 262126, 248, 4084, 1014, 4194282, 248, 1048556, 4084, 262126, 4084, 268435428, 248, 1073741794, 65520, 1048556, 65520, 16777192, 4084, 68719476700, 262126, 16777192, 65520

Offset: 1

Author

Vincenzo Librandi, Jun 04 2014

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A066781, A100371.

Programs

Magma

[2^EulerPhi(n)-EulerPhi(n): n in [1..40]];

Maple

with(numtheory); A243306:=n->2^phi(n)-phi(n); seq(A243306(n), n=1..50); # Wesley Ivan Hurt, Jun 04 2014

Mathematica

Table[2^EulerPhi[n] - EulerPhi[n], {n, 1, 50}]
2^#-#&/@EulerPhi[Range[50]] (* Harvey P. Dale, Dec 19 2017 *)

Formula

a(n) = A066781(n) - A000010(n). - Wesley Ivan Hurt, Jun 04 2014