login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063868 Solutions to phi(x + omega(x)) = phi(x) + d(x), where phi() = A000010(), d() = A000005() and omega() = A001221(). 1
33, 72, 1293, 4187, 7169, 8466, 23086, 24881, 25019, 59987, 77057, 143369, 150419, 176715, 205727, 215069, 220817, 359499, 418307, 1239869, 1887239, 2123583, 2229011, 2262107, 2303837, 2458397, 2502977, 3495954, 3693419, 4279859 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..735 (terms < 10^11, first 60 terms from Harry J. Smith)

MATHEMATICA

Select[Range[5000], EulerPhi[# + PrimeNu[#]] == EulerPhi[#] + DivisorSigma[0, #] &] (* G. C. Greubel, Apr 23 2017 *)

PROG

(PARI) for(n=1, 10^7, if(eulerphi(n+omega(n))==eulerphi(n)+numdiv(n), print1(n, ", ")))

(PARI) { n=0; for (m=1, 10^9, if(eulerphi(m + omega(m)) == eulerphi(m) + numdiv(m), write("b063868.txt", n++, " ", m); if (n==60, break)) ) } \\ Harry J. Smith, Sep 01 2009

CROSSREFS

Cf. A000010, A000005, A001221.

Sequence in context: A044516 A015722 A103046 * A184417 A240884 A049012

Adjacent sequences: A063865 A063866 A063867 * A063869 A063870 A063871

KEYWORD

nonn

AUTHOR

Jason Earls, Aug 26 2001

EXTENSIONS

a(20) from Thomas Baruchel, Oct 19 2003

a(21)-a(30) from Donovan Johnson, Aug 03 2009

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 3 00:23 EST 2022. Contains 358510 sequences. (Running on oeis4.)