A088557 Least even leg of primitive Pythagorean triangles with odd leg 2n+1.

4, 12, 24, 40, 60, 84, 8, 144, 180, 20, 264, 312, 364, 420, 480, 56, 12, 684, 80, 840, 924, 28, 1104, 1200, 140, 1404, 48, 176, 1740, 1860, 16, 72, 2244, 260, 2520, 2664, 308, 36, 3120, 3280, 3444, 132, 416, 3960, 60, 476, 168, 4704, 20, 5100, 5304, 88, 5724, 5940

Offset: 1

Author

Lekraj Beedassy, Nov 17 2003

Keywords

• nonn

Comments

a(n) shares identical entries with A046092(n) except for n=(A081934 - 1)/2.

Links

• Jean-François Alcover, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A088558, A096891-A096900.

Programs

Mathematica

a[n_] := 2k /. Solve[k > 0 && 1 < h < 2k + 2n + 1 && (2k)^2 + (2n + 1)^2 == h^2 && GCD[2k, 2n + 1, h] == 1, {k, h}, Integers][[1]];
a /@ Range[54] (* Jean-François Alcover, Mar 05 2020 *)

Extensions

Corrected and extended by Ray Chandler, Jul 14 2004