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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A336890 Numbers that eventually reach the fixed point 8208 under "x --> sum of the fourth powers of digits of x". 1
 12, 17, 21, 46, 64, 71, 102, 107, 120, 137, 145, 154, 170, 173, 201, 210, 224, 242, 279, 288, 297, 317, 349, 357, 371, 375, 379, 394, 397, 406, 415, 422, 439, 451, 460, 493, 514, 537, 541, 573, 599, 604, 640, 701, 710, 713, 729, 731, 735, 739, 753, 792, 793, 828, 882, 927, 934, 937, 943, 959, 972, 973, 995 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE 12 --> 1^4+2^4 = 17 --> 1^4+7^4 = 2402 --> 2^4+4^4+0^4+2^4 = 288 --> 2^4+8^4+8^4 = 8208. MAPLE V:= Vector(32805): V[8208]:= true: g:= proc(n) local L, t;   add(t^4, t = convert(n, base, 10)) end proc: f:= proc(n) local x, S; global V;   if n <= 32805 then      if V[n] <> 0 then return V[n]      else S:= [n]      fi   else S:= []   fi;   x:= n;   do     x:= g(x);     if V[x] <> 0 then        V[S]:= V[x];        return V[x]     elif member(x, S) then        V[S]:= false;        return false     fi;     if x <= 32805 then S:= [op(S), x] fi;   od; end proc; select(f, [\$1..10000]); # Robert Israel, Sep 03 2020 MATHEMATICA okQ[n] := MemberQ[NestList[Total[IntegerDigits[#]^4]&, n, 30], 8208]; Select[Range[1000], okQ] CROSSREFS Cf. A219111, A031185, A031184. Sequence in context: A162918 A105018 A154488 * A302359 A214514 A188004 Adjacent sequences:  A336887 A336888 A336889 * A336891 A336892 A336893 KEYWORD nonn,base AUTHOR Sergio Falcon, Aug 07 2020 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 19 04:31 EDT 2022. Contains 356216 sequences. (Running on oeis4.)