A247794 - OEIS

%I #7 Aug 20 2015 10:43:13

%S 0,3,5,12,22,59,135,289,1018,2326

%N a(n)^3 is the least cube to contain exactly n distinct digits.

%C "...at least n..." and "...exactly n..." yield the same sequence (i.e. this sequence is strictly increasing).

%t With[{cbs=Table[{n,Count[DigitCount[n^3],_?(#>0&)]},{n,2500}]},Join[{0}, Transpose[Table[SelectFirst[cbs,#[[2]]==i&],{i,2,10}]][[1]]]] (* The program uses the SelectFirst function from Mathematica version 10 *) (* _Harvey P. Dale_, Aug 20 2015 *)

%o (PARI)

%o a(n)= k=0;while(#vecsort(digits(k^3),,8)!=n,k++);k

%o vector(10,n,a(n))

%Y Cf. A054039.

%K nonn,fini,full,base,easy

%O 1,2

%A _Derek Orr_, Sep 23 2014