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A272711 Square numbers whose binary reversal is also square. 0


%S 1,4,9,16,36,64,144,256,576,1024,2304,4096,9216,16384,36864,65536,

%T 147456,262144,589824,1048576,2359296,4194304,9437184,16777216,

%U 20457529,37748736,67108864,81830116,143784081,150994944,268435456,327320464,331130809,575136324,603979776

%N Square numbers whose binary reversal is also square.

%C The first term in this sequence whose binary reversal is not 1 or 9 is 20457529 (which is a binary palindrome).

%C The previous comment means that the sequence does not just contain the squares of numbers in A029744. - _R. J. Mathar_, May 06 2016

%t Select[Range[10^5]^2, IntegerQ@ Sqrt@ FromDigits[ Reverse@ IntegerDigits[#, 2], 2] &] (* _Giovanni Resta_, May 05 2016 *)

%o (PARI) lista(nn) = {for (n=1, nn, if (issquare(subst(Polrev(binary(n^2)), x, 2)), print1(n^2, ", ")););} \\ _Michel Marcus_, May 05 2016

%Y Cf. A000290, A030101, A029983, A229687.

%Y Cf. A061457 (analogous in base 10).

%K nonn,base

%O 1,2

%A _Benjamin Przybocki_, May 04 2016

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Last modified December 15 04:23 EST 2019. Contains 329991 sequences. (Running on oeis4.)