A070145 - OEIS

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A070145

Numbers n such that [A070080(n), A070081(n), A070082(n)] is an isosceles integer triangle with integer area.

39, 52, 269, 372, 375, 862, 957, 972, 1204, 1955, 1971, 1988, 2790, 2796, 3818, 5374, 6522, 6880, 6881, 6921, 7234, 7310, 7341, 7360, 9198, 9207, 10272, 14506, 15101, 15177, 15237, 21289, 21493, 21540, 21552, 21589

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..36.

Eric Weisstein's World of Mathematics, Heronian Triangle.

R. Zumkeller, Integer-sided triangles

EXAMPLE

a(1)=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. A070142, A070144, A070139.

Sequence in context: A216978 A252719 A252720 * A133676 A317987 A330219

Adjacent sequences: A070142 A070143 A070144 * A070146 A070147 A070148

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, May 05 2002

STATUS

approved