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A235331 Numbers with odious squares.

%I A235331 #18 Sep 08 2022 08:46:06
%S A235331 1,2,4,5,7,8,9,10,11,14,16,17,18,19,20,22,23,25,28,29,31,32,33,34,35,
%T A235331 36,38,39,40,41,43,44,46,49,50,51,55,56,58,59,62,64,65,66,67,68,70,71,
%U A235331 72,75,76,77,78,79,80,82,85,86,87,88,89,91,92,95,97,98,100
%N A235331 Numbers with odious squares.
%C A235331 Numbers that are sqrt(odious squares).
%H A235331 Vincenzo Librandi, <a href="/A235331/b235331.txt">Table of n, a(n) for n = 1..2600</a>
%F A235331 a(n) = sqrt(A235001(n)).
%e A235331 1 = sqrt(A235001(1)) = sqrt(1).
%e A235331 2 = sqrt(A235001(2)) = sqrt(4).
%e A235331 4 = sqrt(A235001(3)) = sqrt(16).
%e A235331 5 = sqrt(A235001(4)) = sqrt(25).
%t A235331 Select[Range[200], OddQ[DigitCount[#^2, 2][[1]]] &] (* _Vincenzo Librandi_, Jan 31 2018 *)
%o A235331 (Magma) [n : n in [0..130] |IsOdd(&+Intseq(n^2, 2))]; // _Vincenzo Librandi_, Jan 31 2018
%o A235331 (PARI) isok(n) = (hammingweight(n^2) % 2) == 1; \\ _Michel Marcus_, Jan 31 2018
%Y A235331 Cf. A235001, A194991.
%K A235331 nonn,easy
%O A235331 1,2
%A A235331 _Gerasimov Sergey_, Jan 06 2014