This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A120644 #11 Jan 14 2020 01:04:15 %S A120644 12,60,120,168,420,420,360,1260,660,1848,1008,2640,2772,1092,3120, %T A120644 4680,1980,5460,1680,5148,9240,3432,2448,7140,11220,14280,8580,3420, %U A120644 15912,10032,15960,5460,20748,15708,23940,4620,13260,21840,25080,8160,23712 %N A120644 Area common to integer-sided isosceles triangles (x,x,y) and (x,x,z=y+2d), sorted on x > z/2, d being positive. %C A120644 x=A020882(n); y=2*A046086(n); z=2*A046087(n); d=A120682(n). y is twice the height of the other triangle with z as base and conversely. %C A120644 Take the n-th primitive Pythagorean triple (x, y, z) ordered by increasing z, then y. (1/x)^2 + (1/y)^2 = (z/w)^2, where a(n) = w. - _Ivan N. Ianakiev_, Jan 12 2020 %F A120644 a(n) = y*z/4 = A046086(n)*A046087(n) = 2*A120734(n). %e A120644 168 in the sequence refers to the area common to both triangle (25,25,14) and triangle (25,25,48). %K A120644 easy,nonn %O A120644 1,1 %A A120644 _Lekraj Beedassy_, Aug 17 2006, Aug 20 2006