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A057096 Saint-Exupery numbers: ordered products of the three sides of Pythagorean triangles. +0
8
60, 480, 780, 1620, 2040, 3840, 4200, 6240, 7500, 12180, 12960, 14760, 15540, 16320, 20580, 21060, 30720, 33600, 40260, 43740, 49920, 55080, 60000, 65520, 66780, 79860, 92820, 97440, 97500, 103680, 113400, 118080, 120120, 124320 (list; graph; listen)
OFFSET

1,1

COMMENT

It is an open question whether any two distinct Pythagorean Triples can have the same product of their sides.

REFERENCES

R. K. Guy, "Triangles with Integer Sides, Medians and Area." D21 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 188-190, 1994.

LINKS

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

N. des Vallieres and F. D'Agay, SCOMASE, Le Probleme du Pharaon

FORMULA

a(n) =60*A057097(n) =A057098(n)*A057099(n)*A057100(n)

EXAMPLE

a(1)=3*4*5=60

MATHEMATICA

k=5000000; lst={}; Do[Do[If[IntegerQ[a=Sqrt[c^2-b^2]], If[a>=b, Break[]]; x=a*b*c; If[x<=k, AppendTo[lst, x]]], {b, c-1, 4, -1}], {c, 5, 400, 1}]; Union@lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Sep 05 2009]

CROSSREFS

Cf. A009004, A009012, A009111, A020886.

Sequence in context: A020868 A088943 A097387 this_sequence A069140 A101384 A081384

Adjacent sequences: A057093 A057094 A057095 this_sequence A057097 A057098 A057099

KEYWORD

nonn

AUTHOR

Henry Bottomley (se16(AT)btinternet.com), Aug 01 2000

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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