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A235001 Odious squares. 7

%I #8 Jan 14 2014 10:18:25

%S 1,4,16,25,49,64,81,100,121,196,256,289,324,361,400,484,529,625,784,

%T 841,961,1024,1089,1156,1225,1296,1444,1521,1600,1681,1849,1936,2116,

%U 2401,2500,2601,3025,3136,3364,3481,3844,4096,4225,4356,4489,4624,4900,5041,5184,5625

%N Odious squares.

%C This sequence is the intersection of A000069 and A000290. Numbers n^2 such that A159918 is odd.

%H Harvey P. Dale, <a href="/A235001/b235001.txt">Table of n, a(n) for n = 1..1000</a>

%e 16 is a square 4^2 and 16 in base 2 is a 10000, having an odd number of 1's, thus 16 is in this sequence.

%t Select[Range[200]^2,OddQ[DigitCount[#,2,1]]&] (* _Harvey P. Dale_, Jan 14 2014 *)

%Y Cf. A231431 (evil squares).

%K nonn

%O 1,2

%A _Gerasimov Sergey_, Jan 02 2014

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Last modified April 18 14:42 EDT 2024. Contains 371780 sequences. (Running on oeis4.)