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A070142 Numbers n such that [A070080(n), A070081(n), A070082(n)] is an integer triangle with integer area. +0
12
17, 39, 52, 116, 212, 252, 269, 368, 370, 372, 375, 493, 561, 587, 659, 839, 850, 862, 957, 972, 1156, 1186, 1196, 1204, 1297, 1582, 1599, 1629, 1912, 1920, 1955, 1971, 1988, 2115, 2352, 2555, 2574, 2713, 2774, 2778, 2790 (list; graph; listen)
OFFSET

1,1

LINKS

R. Zumkeller, Integer-sided triangles

Eric Weisstein's World of Mathematics, Heronian Triangle.

EXAMPLE

a(2)=39: [A070080(39), A070081(39), A070082(39)] = [5,5,6], area^2 = s*(s-5)*(s-5)*(s-6) with s=A070083(39)/2=(5+5+6)/2=8, area^2=8*3*3*2=16*9 is an integer square, therefore A070086(39)=area=4*3=12.

CROSSREFS

Cf. A070088, A070149, A070143, A070144, A070145, A051516, A069594, A069597, A070136, A070137, A070209.

Sequence in context: A051779 A139579 A125248 this_sequence A070143 A140679 A078553

Adjacent sequences: A070139 A070140 A070141 this_sequence A070143 A070144 A070145

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 05 2002

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Last modified September 8 13:07 EDT 2008. Contains 143486 sequences.


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