A135622 - OEIS

%I #5 Mar 31 2012 10:29:28

%S 3,15,48,35,63,128,63,135,243,240,320,99,231,275,495,384,576,768,143,

%T 351,455,819,975,560,896,1008,1344,195,495,675,1215,735,1575,1875,768,

%U 1280,1536,2048,2304,255,663,935,1683,1071,2295,2499,2975,1008,1728

%N 16*Area^2 of integer triangles [A070080(n),A070081(n),A070082(n)].

%C A070086(n) = round(sqrt(a(n))/4).

%F a(n)=(u+v+w)*(-u+v+w)*(u-v+w)*(u+v-w), where u=A070080(n), v=A070081(n), w=A070082(n).

%e A070080(4)=1, A070081(4)=3, A070082(4)=3, so a(4)=(1+3+3)*(-1+3+3)*(1-3+3)*(1+3-3)=35.

%K nonn

%O 1,1

%A _Franz Vrabec_, Feb 29 2008