This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A080035 "Orderly" Friedman numbers (or "good" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order. 7

%I

%S 127,343,736,1285,2187,2502,2592,2737,3125,3685,3864,3972,4096,6455,

%T 11264,11664,12850,13825,14641,15552,15585,15612,15613,15617,15618,

%U 15621,15622,15623,15624,15626,15632,15633,15642,15645,15655,15656

%N "Orderly" Friedman numbers (or "good" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order.

%C Primes in this sequence are listed in A252483. The subsequence A156954 is a "simplified" variant where no parentheses, unary operations (negation) nor concatenation is allowed. - _M. F. Hasler_, Jan 07 2015

%D Credit goes to Mike Reid (Brown University) and Eric Friedman (Stetson University).

%D Colin Rose, "Radical Narcissistic numbers", J. Recreational Mathematics, vol. 33, (2004-2005), pp. 250-254. See page 251.

%H M. Brand, <a href="http://dx.doi.org/10.1016/j.dam.2013.05.027">Friedman numbers have density 1</a>, Discrete Applied Mathematics, Volume 161, Issues 16-17, November 2013, Pages 2389-2395.

%H Ed Copeland and Brady Haran, <a href="https://www.youtube.com/watch?v=I7v2wAXFQpc">Friedman numbers -- Numberphile</a>, 2014

%H Eric Friedman, <a href="http://www.stetson.edu/~efriedma/mathmagic/0800.html">Friedman Numbers</a>.

%H Robert G. Wilson v, <a href="/A080035/a080035.txt">Table of n, a(n) for n = 1..108 </a>.

%e 127 = -1 + 2^7, 343 = (3 + 4) ^ 3, 736 = 7 + 3^6, etc.

%e The 4th "orderly" Freidman number is 1285 = (1 + 2^8) * 5.

%Y Cf. A036057.

%K nonn,base,nice

%O 1,1

%A David Rattner (david_rattner(AT)prusec.com), Mar 14 2003

%E More terms from _Alonso del Arte_, Aug 25 2004

%E Edited by _M. F. Hasler_, Jan 07 2015

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.