%I #11 Feb 16 2025 08:32:46
%S 39,52,269,372,375,862,957,972,1204,1955,1971,1988,2790,2796,3818,
%T 5374,6522,6880,6881,6921,7234,7310,7341,7360,9198,9207,10272,14506,
%U 15101,15177,15237,21289,21493,21540,21552,21589
%N Numbers n such that [A070080(n), A070081(n), A070082(n)] is an isosceles integer triangle with integer area.
%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HeronianTriangle.html">Heronian Triangle</a>.
%H R. Zumkeller, <a href="/A070080/a070080.txt">Integer-sided triangles</a>
%e 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.
%Y Cf. A070142, A070144, A070139.
%K nonn,changed
%O 1,1
%A _Reinhard Zumkeller_, May 05 2002