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A127923 Difference between squares of legs of primitive Pythagorean triangles, sorted (with multiplicity). 1
7, 41, 119, 161, 239, 527, 721, 959, 1081, 1241, 1393, 1519, 2047, 3281, 3479, 3713, 4207, 4633, 4681, 4879, 5593, 6647, 6887, 7327, 8119, 9401, 9641, 10199, 11753, 12121, 12319, 12593, 16999, 19159, 19199, 19873, 20447, 22393, 23359, 24521, 24521 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This is the sorted sequence of all products A120681(i)*A120682(i). - R. J. Mathar, Sep 24 2007
The sequence is conjectural (and may miss entries) because it is generated from a finite list of primitive Pythagorean triangles. The associated lengths in a^2+b^2=c^2 are (a,b)=(3,4), (21,20), (5,12), (15,8), (119,120), (7,24), (55,48), (65,72), (35,12), (45,28), (697,696), (9,40), (33,56), (105,88), (11,60), (63,16), (297,304), (77,36), (91,60), (39,80), (403,396), (133,156), (13,84), (207,224), (4059, 4060), (99,20), (171,140), (85,132), (117,44), (275,252), (15,112), (153,104), (51,140), (555,572), (95,168), (143,24), (17,144), (253, 204), (225,272), (165,52), (1755,1748), (429,460),... with gcd(a, b)=1 and |a^2-b^2| in the sequence. - R. J. Mathar, Sep 24 2007
Confirmed sequence is accurate and complete. Observe that both b-a and b+a must be in A058529. Running through the possible combinations of those values with products below 25000 that produce values of a and b that are legs of primitive Pythagorean triangles confirms list is correct. Note that terms of this sequence must also be in A058529. - Ray Chandler, Apr 11 2010
24521 appears twice in the sequence for (a,b)=(52,165) and (1748,1755). - Ray Chandler, Apr 11 2010
LINKS
CROSSREFS
Sequence in context: A007398 A290204 A138629 * A230018 A165563 A034575
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Feb 06 2007
EXTENSIONS
More terms from R. J. Mathar, Sep 24 2007
Removed "conjectural" from description by Ray Chandler, Apr 11 2010
STATUS
approved

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Last modified April 19 15:11 EDT 2024. Contains 371794 sequences. (Running on oeis4.)