%I
%S 13,175,490,85,308,13475,3179,9295,19760,60775,55315,225420,203665,
%T 9724,512050,568854,207740,252700,2684396,8695050,1221025,140875,
%U 3121937,311220,21390460,12289004,17331908,20074032,44144100,18055947,21118608,21017325,40245205,4418232
%N 1/15840 of the volume of a primitive 3simplex.
%C The volume of every primitive trirectangular tetrahedron with integer sides is divisible by 15840. See A031173 for more comments.
%C These primitive trirectangular tetrahedrons are primitive 3simplices.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TrirectangularTetrahedron.html">Trirectangular Tetrahedron</a>
%F a(n) = (1/15840)*A031173(n)*A031174(n)*A031175(n)/6.
%Y Cf. A031173, A031174, A031175.
%K nonn
%O 1,1
%A _Ralf Steiner_, Nov 23 2017
