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!)
 A164323 Numbers n such that n=prime(P)+phi(P), where P is the product of the digits of n. 2
 15, 383, 629, 8297 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The product of the digits of next term (if it exists) is greater than 2*10^8. The sequence is finite since prime(P) ~= P*log(P) and phi(P) < P, while n > 10^(log(P)/log(9)) - 1 > P^1.047. [From Max Alekseyev] LINKS EXAMPLE 8297=prime(8*2*9*7)+phi(8*2*9*7), so 8297 is in the sequence. MATHEMATICA Do[If[n=Prime[m]+Eulerphi[m]; m==Apply[Times, IntegerDigits[n]], Print[n]], {m, 200000000}] CROSSREFS Cf. A000040, A000010, A164322, A164324. Sequence in context: A035274 A324415 A145409 * A129615 A286139 A069990 Adjacent sequences:  A164320 A164321 A164322 * A164324 A164325 A164326 KEYWORD base,more,nonn,fini AUTHOR Farideh Firoozbakht, Aug 13 2009 EXTENSIONS Keyword fini added by Max Alekseyev, Dec 14 2011 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 April 11 16:42 EDT 2021. Contains 342888 sequences. (Running on oeis4.)