%I A053457
%S A053457 0,0,2,6,12,16,26,38,48,60,78,94,108,128,154,174,196,224,250,278,312,
%T A053457 344,378,410,452,484,526,574,612,652,698,754,800,848,906,958,1012,1068,
%U A053457 1130,1190,1252,1316,1378,1446,1516,1588,1654,1730,1808,1880,1954
%N A053457 Open disk numbers (version 2): a(n)= number of points (i,j), i,j, integers, 
               contained in a open disk of diameter n, centered at (0,1/2).
%C A053457 a(n)/(n/2)^2->Pi
%Y A053457 A053414, A053456-A053459.
%Y A053457 Sequence in context: A088915 A084790 A130237 this_sequence A154030 A055560 
               A108727
%Y A053457 Adjacent sequences: A053454 A053455 A053456 this_sequence A053458 A053459 
               A053460
%K A053457 easy,nonn
%O A053457 0,3
%A A053457 Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Jan 13 2000