login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A039773 phi(n) is equal to the sum of prime factors and exponents of n-1. 0
5, 34, 66, 130, 490, 18130 (list; graph; refs; listen; history; text; internal format)
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 A135973

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified January 18 18:32 EST 2018. Contains 297864 sequences.