%I A113422
%S A113422 0,2,7,15,27,42,60,82,107,135,167,202,240,282,327,375,427,482,540,602,
%T A113422 667,735,807,882,960,1042,1127,1215,1307,1402,1500,1602,1707,1815,1927,
%U A113422 2042,2160,2282,2407,2535,2667,2802,2940,3082,3227,3375,3527,3682,3840
%N A113422 a(n)=[(5n^2+1)/3].
%C A113422 If n<a(m) then all integer solutions (i,j,k) of 2*i^2+2*j^2+3*k^2-2*i*k=n 
               satisfy max(|i|,|j|,|k|)<m.
%F A113422 G.f.: (2x+3x^2+3x^3+2x^4)/((1-x)^2(1-x^3)). a(-n)=a(n). a(3n)=15n^2, 
               a(3n+1)=15n^2+10n+2.
%o A113422 (PARI) a(n)=(5*n^2+1)\3
%Y A113422 Sequence in context: A167543 A029888 A005449 this_sequence A061802 A003452 
               A000148
%Y A113422 Adjacent sequences: A113419 A113420 A113421 this_sequence A113423 A113424 
               A113425
%K A113422 nonn
%O A113422 0,2
%A A113422 Michael Somos, Oct 31 2005