A034025 - OEIS

A034025

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

25, 50, 125, 169, 250, 289, 325, 338, 425, 578, 625, 650, 725, 841, 845, 850, 925, 1025, 1250, 1325, 1369, 1445, 1450, 1525, 1625, 1681, 1682, 1690, 1825, 1850, 2050, 2125, 2197, 2225, 2425, 2525, 2650, 2725, 2738, 2809, 2825, 2873, 2890

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OFFSET

0,1

LINKS

Table of n, a(n) for n=0..42.

MATHEMATICA

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-François Alcover, Jan 25 2013 *)

CROSSREFS

Cf. A001481, A008784, A022544, A034023-.

Sequence in context: A045195 A232438 A360017 * A253017 A042236 A042238

Adjacent sequences: A034022 A034023 A034024 * A034026 A034027 A034028

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved