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Search: id:A065607
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| A065607 |
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Related to reciprocal Pythagorean triples: 1/a(n)^2 + 1/k^2 = 1/j^2 has an integer solution (k,j) with k<a(n). |
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+0
4
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| 20, 40, 60, 80, 100, 120, 140, 156, 160, 180, 200, 220, 240, 255, 260, 280, 300, 312, 320, 340, 360, 380, 400, 420, 440, 460, 468, 480, 500, 510, 520, 540, 560, 580, 600, 600, 609, 620, 624, 640, 660, 680, 700, 720, 740, 760, 765, 780, 780, 800, 820, 840
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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The entries 600 and 780 occur in two solutions each; the others entries uniquely.
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MAPLE
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a := []; for n from 2 to 1000 do for m from 2 to n do if (numer(simplify(1/n^2+1/m^2))=1) then if type(sqrt(denom(simplify(1/n^2+1/m^2))), integer)=true then print(n, m, ifactor(n), ifactor(m), ifactor(denom(simplify(1/n^2+1/m^2))), sqrt(denom(simplify(1/n^2+1/m^2)))); printlevel := -1; a := [op(a), n]; printlevel := 1 fi fi od od; print(a);
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CROSSREFS
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Sequence in context: A046794 A104153 A049057 this_sequence A008602 A061830 A041790
Adjacent sequences: A065604 A065605 A065606 this_sequence A065608 A065609 A065610
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KEYWORD
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nonn
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AUTHOR
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Len Smiley (smiley(AT)math.uaa.alaska.edu), Dec 01 2001
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