A070147 Numbers n such that [A070080(n), A070081(n), A070082(n)] is an obtuse integer triangle with integer area.

52, 252, 368, 372, 561, 659, 839, 957, 1156, 1186, 1204, 1582, 1912, 1920, 1971, 2115, 2713, 2774, 2790, 3251, 3473, 3728, 3746, 4286, 4307, 4313, 4330, 5008, 5272, 5374, 6369, 6389, 6432, 6776, 6881, 7223, 7310, 7341

Offset

1,1

Links

Table of n, a(n) for n=1..38.

Eric Weisstein's World of Mathematics, Heronian Triangle.

Eric Weisstein's World of Mathematics, Obtuse Triangle.

R. Zumkeller, Integer-sided triangles

Example

a(1)=52: [A070080(52), A070081(52), A070082(52)] = [5,5,8]: A070085(52)=5^2+5^2-8^2=-14<0 and area^2 = s*(s-5)*(s-5)*(s-6) with s=A070083(52)/2=(5+5+8)/2=9, area^2=9*4*4*1=16*9 is an integer square, therefore A070086(52)=area=4*3=12.

Crossrefs

Cf. A070142, A070136, A070146, A070141.

Sequence in context: A023417 A122239 A086860 * A236517 A320556 A252335

Adjacent sequences: A070144 A070145 A070146 * A070148 A070149 A070150

Keyword

nonn

Author

Reinhard Zumkeller, May 05 2002

Status

approved