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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A113622 Numbers n such that the reverse of the representation of phi(n) is a substring of n, in base 10. 1
1, 21, 63, 270, 291, 1065, 2991, 6102, 10087, 10279, 10654, 16528, 144069, 1440069, 10253179, 10657654, 14400069, 16163608, 46676013, 69460293, 2346534651, 2369436474, 6313047393, 10270341004, 10657657654, 14406534069, 23400000651 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

If p=480...023 is prime, then n=3*p=1440...069 and phi(n)=960...044, thus n belongs to the sequence.

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

phi(1_440069) = 960044.

MATHEMATICA

lst = {}; Do[If[{}!= StringPosition[ToString@n, StringReverse@ToString@EulerPhi@n], AppendTo[lst, n], {n, 2*10^7}]; lst

CROSSREFS

Cf. A069215.

Sequence in context: A033850 A251213 A170930 * A069215 A115921 A251808

Adjacent sequences:  A113619 A113620 A113621 * A113623 A113624 A113625

KEYWORD

base,nonn

AUTHOR

Giovanni Resta, Jan 26 2006

EXTENSIONS

a(19)-a(27) from Donovan Johnson, May 11 2010

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 29 09:29 EDT 2020. Contains 337428 sequences. (Running on oeis4.)