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A155150 Numbers k such that k^4 has exactly 4 distinct decimal digits.

%I A155150 #19 Oct 01 2024 15:45:20
%S A155150 6,7,8,15,19,21,24,27,28,36,39,40,42,46,50,52,57,64,67,69,70,80,85,88,
%T A155150 90,101,110,131,150,160,183,190,202,203,340,400,433,500,570,670,700,
%U A155150 800,843,850,900,1001,1010,1100,1171,1500,1600,1900,2673,2868,3400,4000
%N A155150 Numbers k such that k^4 has exactly 4 distinct decimal digits.
%H A155150 Harvey P. Dale, <a href="/A155150/b155150.txt">Table of n, a(n) for n = 1..100</a>
%t A155150 ddd4Q[n_]:=Count[DigitCount[n^4],_?(#>0&)]==4; Select[Range[5000],ddd4Q] (* _Harvey P. Dale_, Nov 10 2012 *)
%t A155150 Select[Range[4000], Length[Union[IntegerDigits[#^4]]]==4&] (* _Vincenzo Librandi_, Nov 07 2014 *)
%o A155150 (Python)
%o A155150 A155150_list, m = [], [24, -36, 14, -1, 0]
%o A155150 for n in range(1, 10**3+1):
%o A155150     for i in range(4):
%o A155150         m[i+1] += m[i]
%o A155150     if len(set(str(m[-1]))) == 4:
%o A155150         A155150_list.append(n) # _Chai Wah Wu_, Nov 05 2014
%o A155150 (Magma) [n: n in [0..4000] | #Set(Intseq(n^4)) eq 4]; // _Vincenzo Librandi_, Nov 07 2014
%Y A155150 Cf. A155148, A155149
%K A155150 nonn,base
%O A155150 1,1
%A A155150 _Dmitry Kamenetsky_, Jan 21 2009
%E A155150 Edited by _Charles R Greathouse IV_, Aug 02 2010