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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A233451 Numbers k such that k^5 starts with k itself (in base 10). 7

%I #21 Aug 27 2023 16:39:19

%S 0,1,10,18,100,178,1000,10000,17783,31623,100000,177828,316228,

%T 1000000,10000000,100000000,1000000000,5623413252,10000000000,

%U 100000000000,177827941004,316227766017,1000000000000,1778279410039,10000000000000,31622776601684

%N Numbers k such that k^5 starts with k itself (in base 10).

%e 18^5 = 1889568 begins with 18, so 18 is in the sequence.

%t kmax=10^6; Select[Range[0,kmax],FromDigits[Drop[IntegerDigits[#^5],-(IntegerLength[#^5]-IntegerLength[#])]]==# &] (* _Stefano Spezia_, Aug 27 2023 *)

%o (PARI) r=54; print1(1, ", "); e=5; for(n=2, r, p=round((10^(1/(e-1)))^n); f=p^e; b=10^(#Str(f)-#Str(p)); if((f-lift(Mod(f, b)))/b==p, print1(p, ", ")));

%Y Cf. A052210, A052211, A233452, A233453, A233454, A233455, A233456.

%K nonn,base,easy

%O 1,3

%A _Arkadiusz Wesolowski_, Dec 10 2013

%E 0 inserted by _Juhani Heino_, Aug 31 2015

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 15:18 EDT 2024. Contains 371960 sequences. (Running on oeis4.)