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A244603 Least number k such that n^k contains the digit n n times. 2

%I #8 Mar 18 2023 11:37:52

%S 1,18,21,32,30,38,33,55,69

%N Least number k such that n^k contains the digit n n times.

%e 2^18 is the first power of 2 to contain 2 twice. So a(2) = 18.

%e 3^21 is the first power of 3 to contain 3 three times. So a(3) = 21.

%o (Python)

%o def tes(n):

%o for k in range(1,10**3):

%o if(str(n**k).count(str(n))) == n:

%o return k

%o n = 1

%o while n < 10:

%o print(tes(n),end=', ')

%o n += 1

%K nonn,base,fini,full

%O 1,2

%A _Derek Orr_, Jul 01 2014

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)