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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A087270 Solutions to gcd(x,pi(x)) = gcd(x, A000720(x)) > 1. Numbers x such that x and pi(x) have common divisor larger than one. 0
4, 6, 8, 10, 14, 15, 16, 20, 22, 24, 27, 30, 33, 38, 39, 40, 44, 46, 48, 50, 51, 54, 56, 58, 62, 63, 64, 66, 72, 75, 77, 78, 80, 82, 90, 92, 93, 94, 96, 100, 102, 105, 108, 114, 115, 116, 117, 118, 120, 122, 123, 124, 125, 126, 132, 134, 136, 138, 140, 142, 144, 146 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..62.

MATHEMATICA

t=Table[GCD[w, PrimePi[w]], {w, 1, 1000}]; Flatten[Position[Sign[t-1], 1]]

CROSSREFS

Cf. A007053, A000720, A087266-A087269, A057809.

Sequence in context: A084808 A310660 A031020 * A316262 A075124 A067315

Adjacent sequences:  A087267 A087268 A087269 * A087271 A087272 A087273

KEYWORD

nonn

AUTHOR

Labos Elemer, Sep 16 2003

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 July 3 16:12 EDT 2022. Contains 355055 sequences. (Running on oeis4.)