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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A251362 Numbers n such that n is the concatenation of distinct prime factors of phi(n), in increasing order. 3
25, 235741, 23517131 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term must be greater than 10^8.

Numbers n such that n = A084317(A000010(n)). - Michel Marcus, Dec 06 2014

LINKS

Table of n, a(n) for n=1..3.

EXAMPLE

25 is in the sequence since phi(25)=2^2*5, 235741 is in the sequence since phi(235741)=2^4*3^2*5*7*41, and 23517131 is in the sequence since phi(23517131)=2^7*3*5^2*17*131.

MATHEMATICA

a251362[n_Integer] := Rest@ Select[Range[n], # ==

FromDigits[Flatten@IntegerDigits[First@Transpose@FactorInteger[EulerPhi[#]]]] &]; a251362[10^6] (* Michael De Vlieger, Dec 03 2014 *)

CROSSREFS

Cf. A000010, A000040, A084317, A251363.

Sequence in context: A068737 A151649 A122500 * A196520 A228536 A191559

Adjacent sequences:  A251359 A251360 A251361 * A251363 A251364 A251365

KEYWORD

nonn,base,more,bref

AUTHOR

Jahangeer Kholdi, Dec 03 2014

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 October 20 22:44 EDT 2019. Contains 328291 sequences. (Running on oeis4.)