A039773 phi(n) is equal to the sum of prime factors and exponents of n-1.

5, 34, 66, 130, 490, 18130

Offset

1,1

Links

Table of n, a(n) for n=1..6.

Example

phi(34)=16, 33=3^1*11^1, 3+1+11+1=16.

Mathematica

Select[Range[20000], Total[Flatten[FactorInteger[#-1]]]==EulerPhi[#]&] (* Harvey P. Dale, Mar 27 2017 *)

Crossrefs

Cf. A000010, A008474.

Sequence in context: A268281 A223137 A068560 * A289947 A272955 A317297

Adjacent sequences: A039770 A039771 A039772 * A039774 A039775 A039776

Keyword

nonn

Author

Olivier Gérard

Extensions

Next term if it exists is >= 5*10^7 - Naohiro Nomoto, Jun 24 2001.

Status

approved