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%I #9 Mar 26 2019 08:27:37
%S 1,1,4,5,5,5,11,11,12,12,12,15,21,21,21,22,22,22,28,28,34,34,34,34,35,
%T 35,38,44,44,44,50,50,50,50,50,51,57,57,63,63,63,63,69,69,69,69,69,72,
%U 79,79,79,85,85,85,85,85,91,91,91,91,97,97,103,104,104,104
%N Number of integer solutions to x^2 + x*y + y^2 <= n excluding (0,0), divided by 2.
%e a(1)=a(2)=(2/2)=1: 2 solutions (-1,1),(1,-1);
%e a(3)=(8/2)=4: 2 solutions for n<3 and the 6 solutions (1,1), (-1,-1), (1,-2), (2,-1), (-1,2), (-2,1);
%e a(4)=a(5)=a(6)=10/2=5: 8 solutions for n<6 and the 2 solutions (-2,2), (2,-2).
%Y Cf. A014201, A014202, A198799, A230655, A300419.
%K nonn
%O 1,3
%A _Hugo Pfoertner_, Mar 25 2019