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A089015
Least odd short leg of n primitive Pythagorean triangles.
0
3, 33, 105, 315, 9009, 2145, 1155, 3045
OFFSET
1,1
COMMENTS
a(9) is greater than 30000000, if it exists. a(12) through a(16) are 204435, 26565, 15015, 41055, 153153. - Joshua Zucker, May 13 2006
EXAMPLE
a(3)=105 because 105 is the first odd short leg of the 3 primitive Pythagorean triples, viz. (105, 208, 233), (105, 608, 617), (105, 5512, 5513), followed by such triples of primitive Pythagorean triangles each starting with 165, 195, 231, 255, 273, 285, 429, 715, 765, 819, 935, 969, 1001, ...
Similarly, a(4)=315 because the group of 4 odd-short-leg primitive Pythagorean triangles (315, 572, 653), (315, 988, 1037), (315, 1972, 1997), (315, 49612, 49613) precedes all such groups of 4 primitive Pythagorean triangles each starting with 385, 455, 495, 693, ...
CROSSREFS
Cf. A083883.
Sequence in context: A153783 A048911 A239345 * A292453 A292733 A062215
KEYWORD
hard,more,nonn
AUTHOR
Lekraj Beedassy, Nov 04 2003
EXTENSIONS
More terms from Joshua Zucker, May 13 2006
STATUS
approved