The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A064158 Integers n such that (x1*x2*..xk)^(x1+x2+..xk) = (x1+x2+..xk)^(x1*x2*...xk) where x1x2..xk are the digits of n in base 10. 2
 1, 2, 3, 4, 5, 6, 7, 8, 9, 22, 112, 121, 123, 132, 211, 213, 231, 312, 321, 1124, 1142, 1214, 1241, 1412, 1421, 2114, 2141, 2411, 4112, 4121, 4211, 11125, 11133, 11152, 11215, 11222, 11251, 11313, 11331, 11512, 11521, 12115, 12122, 12151, 12212 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS With the exception of only 112,121, and 211, each term of this sequence satisfies (sum of digits) equals (product of digits). For 112, 121, and 211, the sum of the digits is 4, the product of the digits is 2, and the terms qualify because 2^4 equals 4^2. [From Harvey P. Dale, Sep 30 2011] LINKS Harvey P. Dale, Table of n, a(n) for n = 1..179 EXAMPLE 22 belongs to the sequence because (2*2)^(2+2)=(2+2)^(2*2) MATHEMATICA okQ[n_]:=Module[{idn=IntegerDigits[n], t, p}, t= Times@@idn; p=Total[idn]; t^p==p^t]; Select[Range[12500], okQ] CROSSREFS Sequence in context: A232709 A249334 A338257 * A064702 A034710 A305257 Adjacent sequences: A064155 A064156 A064157 * A064159 A064160 A064161 KEYWORD easy,nonn,base AUTHOR Felice Russo, Sep 14 2001 EXTENSIONS More terms from Jason Earls, Dec 04 2001 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 May 29 05:33 EDT 2024. Contains 372921 sequences. (Running on oeis4.)