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A072294 Areas of primitive Heronian triangles sorted by longest side, then by middle side and finally shortest side. 6

%I #31 Nov 14 2019 15:40:13

%S 6,12,12,30,60,24,84,36,60,120,66,42,84,126,60,90,84,168,36,204,210,

%T 210,60,120,132,72,84,252,360,114,156,180,210,420,120,210,420,168,420,

%U 240,468,126,180,336,360,420,264,330,252,168,504,420,780,420,306,456,156

%N Areas of primitive Heronian triangles sorted by longest side, then by middle side and finally shortest side.

%H Ray Chandler, <a href="/A072294/b072294.txt">Table of n, a(n) for n = 1..10000</a> (first 2197 terms from Zak Seidov)

%H A. Dendane, <a href="http://www.analyzemath.com/Geometry_calculators/herons_area_triangle.html">Heron's Formula for Area of a Triangle-Geometry Calculator</a>

%H Zak Seidov, <a href="/A072294/a072294_1.txt">Table of n=1..6093, A072294(n), A120131(n), A120132(n), A120133(n)</a> (with A120131(n) <=1000)

%H Michael Somos, <a href="http://grail.eecs.csuohio.edu/~somos/tritab.html">Heronian Triangle Table</a>

%H P. Yiu, <a href="http://math.fau.edu/yiu/RecreationalMathematics2003.pdf">Heron triangles with sides < 100</a> Appendix Chap. 9.3 pp. 81/360 in 'Recreational Mathematics'.

%t nn = 200; lst = {}; Do[s = (a + b + c)/2; If[IntegerQ[s] && GCD[a, b, c] == 1, area2 = s (s - a) (s - b) (s - c); If[area2 > 0 && IntegerQ[Sqrt[area2]], AppendTo[lst, Sqrt[area2]]]], {a, nn}, {b, a}, {c, b}]; lst (* _T. D. Noe_, Mar 23 2011 *)

%Y Cf. A120131, A120132, A120133, A055595.

%K nonn

%O 1,1

%A _Lekraj Beedassy_, Jul 12 2002

%E More terms from _Ray Chandler_, Jul 02 2004

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Last modified April 25 07:07 EDT 2024. Contains 371964 sequences. (Running on oeis4.)