%I #8 May 24 2015 08:51:15

%S 2,3,4,4,6,6,4,10,5,9,12,10,6,6,11,13,8,5,13,14,6,15,12,14,10,14,10,7,

%T 16,12,16,18,21,14,6,20,20,16,17,8,7,8,18,17,18,10,24,21,24,8,22,22,

%U 26,14,19,14,24,24,24,24,12,25,30,18,18,7,9,28,28,20,16,19,8,27,21,27,18

%N Primitive Pythagorean Quadruples a^2+b^2+c^2=d^2, 0<a<=b<=c<=d, gcd(a,b,c,d)=1, sorted by d, then c, then b; sequence gives b values.

%H Ivan Neretin, <a href="/A096908/b096908.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PythagoreanQuadruple.html">Pythagorean Quadruple.</a>

%t mx = 50; res = {}; Do[If[GCD[b, c, d] > 1, Continue[]]; If[IntegerQ[a = Sqrt[d^2 - b^2 - c^2]] && a > 0 && a <= b, AppendTo[res, {a, b, c, d}]], {d, mx}, {c, d}, {b, c}]; res[[All, 2]] (* _Ivan Neretin_, May 24 2015 *)

%Y Cf. A096907, A096909, A096910.

%K nonn,look

%O 1,1

%A _Ray Chandler_, Aug 15 2004