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 A104026 Numbers that can be represented as k^2*j, 0 < j <= k but not if gcd(k, j) = 1. 2

%I

%S 32,72,108,128,200,243,288,384,392,432,486,500,512,600,675,800,864,

%T 972,1125,1152,1176,1323,1350,1372,1440,1536,1568,1728,1944,1960,2000,

%U 2048,2187,2250,2400,2560,2592,2646,2700,2904,3087,3125,3200,3240,3267,3380

%N Numbers that can be represented as k^2*j, 0 < j <= k but not if gcd(k, j) = 1.

%C The complement of A104020 and A104021.

%e 32 is in the list because 32 = 4^2*2 but gcd(4,2) = 2.

%t A104020 = Take[Union[Flatten[Table[k^2 * j, {k, 70}, {j, k - 1}]]], 200]; A104021 = Take[Union[Flatten[Table[If[GCD[k, j] == 1, k^2 * j, {}], {k, 70}, {j, k - 1}]]], 150]; Complement[A104020, A104021]

%Y Cf. A104020, A104021.

%K nonn

%O 1,1

%A _Leroy Quet_ and _Robert G. Wilson v_, Feb 25 2005

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Last modified September 16 15:58 EDT 2021. Contains 347473 sequences. (Running on oeis4.)