The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 9 00:09 EDT 2021. Contains 343685 sequences. (Running on oeis4.)