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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137598 Numbers n such that phi(n)=reversal(n)+1. 2
 1541, 13811, 30590, 57871382, 95793434, 99178725, 3664133243, 7699397795, 1992945982991, 7028723775455 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(11) > 10^13. - Giovanni Resta, Aug 12 2019 LINKS Table of n, a(n) for n=1..10. EXAMPLE phi(95793434)=43439760=43439759+1=reversal(95793434)+1, so 95793434 is in the sequence. MATHEMATICA Do[If[EulerPhi@n==FromDigits@Reverse@IntegerDigits@n+1, Print[n]], {n, 255000000}] PROG (PARI) isok(m) = eulerphi(m) == fromdigits(Vecrev(digits(m)))+1; \\ Michel Marcus, Aug 13 2019 CROSSREFS Cf. A000010, A004086, A130000, A137599. Sequence in context: A092717 A203134 A083734 * A252966 A133560 A232102 Adjacent sequences: A137595 A137596 A137597 * A137599 A137600 A137601 KEYWORD nonn,base,more AUTHOR Farideh Firoozbakht, Feb 23 2008 EXTENSIONS a(6)-a(8) from Giovanni Resta, Oct 28 2012 a(9)-a(10) from Giovanni Resta, Aug 12 2019 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.

Last modified August 7 08:03 EDT 2024. Contains 375008 sequences. (Running on oeis4.)