Least even leg of primitive Pythagorean triangles with odd leg 2n+1.

Terms

a(0) =4a(1) =12a(2) =24a(3) =40a(4) =60a(5) =84a(6) =8a(7) =144a(8) =180a(9) =20a(10) =264a(11) =312a(12) =364a(13) =420a(14) =480a(15) =56a(16) =12a(17) =684a(18) =80a(19) =840a(20) =924a(21) =28a(22) =1104a(23) =1200a(24) =140a(25) =1404a(26) =48a(27) =176a(28) =1740a(29) =1860