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A034025 Both primitively and imprimitively represented by x^2+y^2. 0

%I

%S 25,50,125,169,250,289,325,338,425,578,625,650,725,841,845,850,925,

%T 1025,1250,1325,1369,1445,1450,1525,1625,1681,1682,1690,1825,1850,

%U 2050,2125,2197,2225,2425,2525,2650,2725,2738,2809,2825,2873,2890

%N Both primitively and imprimitively represented by x^2+y^2.

%t okQ[n_] := (xy = {x, y} /. {ToRules[Reduce[n == x^2 + y^2, {x, y}, Integers]]}; cnt = Count[xy, {x_, y_} /; GCD[x, y] == 1]; Length[xy] > cnt > 0); Reap[For[n = 1, n <= 3000, n++, If[okQ[n], Print[n]; Sow[n]]]][[2, 1]] (* _Jean-Fran├žois Alcover_, Jan 25 2013 *)

%Y Cf. A001481, A008784, A022544, A034023-.

%K nonn

%O 0,1

%A _N. J. A. Sloane_.

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Last modified July 27 11:29 EDT 2021. Contains 346304 sequences. (Running on oeis4.)