A088558 - OEIS

%I #10 Mar 05 2020 08:21:55

%S 3,15,5,63,21,7,45,255,77,9,117,55,165,33,11,1023,285,65,357,39,13,

%T 105,525,247,621,153,725,15,837,119,957,4095,85,273,51,17,1365,345,

%U 133,231,1677,95,1845,57,19,513,2205,1015,2397,609,253,105,2805,713,21,207,325

%N Least odd leg of primitive Pythagorean triangles with even leg 4n.

%H Jean-François Alcover, <a href="/A088558/b088558.txt">Table of n, a(n) for n = 1..1000</a>

%t a[n_] := 2k + 1 /. Solve[k > 0 && 1 < h < 2k + 1 + 4n && (2k + 1)^2 + (4n)^2 == h^2 && GCD[2k + 1, 4n, h] == 1, {k, h}, Integers][[1]];

%t a /@ Range[57] (* _Jean-François Alcover_, Mar 05 2020 *)

%Y Cf. A088557, A096891-A096900.

%K nonn

%O 1,1

%A _Lekraj Beedassy_, Nov 17 2003

%E Extended by _Ray Chandler_, Jul 14 2004