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%I #22 May 28 2023 02:01:04
%S 130,136,160,266,290,296,386,392,416,518,521,523,526,530,536,545,547,
%T 548,556,562,568,578,584,608,641,643,644,652,656,688,706,712,736,778,
%U 802,808,898,904,928,1050,1062,1065,1067,1070
%N Numbers whose base-4 representation contains exactly two 0's and two 2's.
%H Enrique Pérez Herrero, <a href="/A045049/b045049.txt">Table of n, a(n) for n = 1..100000</a>
%t fQ[n_] := Block[{idn = IntegerDigits[n, 4]}, Count[idn, 0] == Count[idn, 2] == 2]; Select[Range@1100, fQ] (* _Robert G. Wilson v_, Dec 11 2017 *)
%o (Python)
%o import numpy as np
%o for a in range(10000):
%o x = np.base_repr(a, base=4)
%o if(x.count("0") == 2 and x.count("2") == 2):
%o print(a)
%o # _Enrique Pérez Herrero_, Dec 06 2017
%Y Cf. A007090.
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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