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%I #13 Jul 02 2016 00:51:24
%S 18,72,98,162,242,245,288,392,490,605,648,722,882,968,980,1058,1152,
%T 1210,1225,1458,1568,1805,1922,1960,2178,2205,2420,2450,2592,2645,
%U 2888,3025,3528,3610,3698,3872,3920,4232,4410,4418,4608,4693,4802,4805,4840,4900,5290
%N Numbers n such that n is the sum of two nonzero squares while A006530(n) is not.
%e 245 is a term because 245 = 5*7^2 = 7^2 + 14^2 and 7 is not the sum of two nonzero squares.
%e 1764 is not a term because 1764 = 2^2*3^2*7^2.
%t nR[n_]:=(SquaresR[2,n] + Plus@@Pick[{-4,4}, IntegerQ/@ Sqrt[{n, n/2}]])/8; Select[ Range[10^4], nR[#] > 0 && Mod[FactorInteger[#][[-1, 1]], 4] == 3 &] (* _Giovanni Resta_, Jun 29 2016 *)
%Y Cf. A000404, A006530.
%K nonn,easy
%O 1,1
%A _Altug Alkan_, Jun 29 2016