A088899 - OEIS

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A088899

T(n,k) = number of ordered pairs of integers (x,y) with x^2/n^2 + y^2/k^2 = 1, 1<=k<=n; triangular array, read by rows.

4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 12, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 12, 4, 4, 4, 4, 12, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 12, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4 (list; table; graph; refs; listen; history; text; internal format)

	OFFSET	`1,1`
	COMMENTS	`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).`
	LINKS	`Table of n, a(n) for n=1..101.` `Eric Weisstein's World of Mathematics, Ellipse`
	CROSSREFS	`Sequence in context: A138908 A032564 A141248 * A066014 A080678 A096300` `Adjacent sequences: A088896 A088897 A088898 * A088900 A088901 A088902`
	KEYWORD	`nonn,tabl`
	AUTHOR	`Reinhard Zumkeller, Oct 21 2003`
	STATUS	`approved`

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Last modified May 23 04:04 EDT 2013. Contains 225585 sequences.