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T(n,k) = number of lattice points on the circumference of an ellipse with semimajor axis = n, semiminor axis = k and center = (0,0).
a(n) = A088897(n) - A088898(n);
T(n,n) = A046109(n).
Table of n, a(n) for n=1..101.
Eric Weisstein's World of Mathematics, Ellipse
Sequence in context: A138908 A032564 A141248 * A258199 A066014 A080678
Adjacent sequences: A088896 A088897 A088898 * A088900 A088901 A088902
Reinhard Zumkeller, Oct 21 2003