%I #8 Jan 24 2015 15:17:05
%S 5,10,15,17,20,30,34,35,37,40,41,43,45,47,51,55,59,60,65,67,68,70,74,
%T 79,80,82,83,86,89,90,94,95,101,102,105,109,110,111,115,118,119,120,
%U 123,127,129,130,131,134,135,136,140,141,145,148,151,153,155,158
%N Positive integers whose square is expressible in exactly one way as x^2 + 5xy + y^2, with 0 < x < y.
%H Colin Barker, <a href="/A254063/b254063.txt">Table of n, a(n) for n = 1..750</a>
%e 5 is in the sequence because the only solution to x^2 + 5xy + y^2 = 25 with 0 < x < y is (x,y) = (1,3).
%Y Cf. A084645, A232437, A248599, A254064.
%K nonn
%O 1,1
%A _Colin Barker_, Jan 24 2015