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Search: id:A156668
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| A156668 |
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Positive integers k such that k^2 = (m^5+n^5)/(m+n) for some co-prime integers m,n. |
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3
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| 1, 11, 101, 13361, 1169341, 1612186411, 1624763543401, 20188985439712961, 240020196429554642201, 29891946989942513908518251, 3506790234728288196345900732301, 5190947078637547438603476743093680561
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OFFSET
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1,2
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FORMULA
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Numerators of rational numbers (81*x^4+540*x^3-8370*x^2+33900*x-47975)/(9*x^2 - 150*x + 445)^2, where x ranges over abscissas of rational points on the elliptic curve y^2 = x^3 - 85/3*x + 1550/27.
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EXAMPLE
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13361 belongs to this sequence since 13361^2 = (35^5 + 123^5) / (35 + 123) with gcd(35,123)=1.
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CROSSREFS
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Cf. A156669, A156670
Sequence in context: A020449 A089971 A082620 this_sequence A103992 A001387 A100580
Adjacent sequences: A156665 A156666 A156667 this_sequence A156669 A156670 A156671
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KEYWORD
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nonn
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AUTHOR
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Max Alekseyev (maxale(AT)gmail.com), Feb 13 2009
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