congruent(n)=
{
if(issquare(n)==1,print(n," is square hence not congruent"),\
k=1;j=0;\
while(k,j=j+1;s=2*j+1;\
 for(t=1,s-1,\
  if(gcd(s,t)==1&&t%2==0,,a=s*t;b=(s^2-t^2)/2;c=(s^2+t^2)/2;\
if(issquare(a*b/(2*n))&&a*b/(2*n)==floor(a*b/(2*n)),r=floor(sqrt(a*b/(2*n)));a=a/r;b=b/r;c=c/r;print(n" is a congruent number: a="a", b="b", c="c);break(4))))))
}

addhelp(congruent , "congruent(n) : searches for a rational right triangle with area n.")

printp("congruent(n) : searches for a rational right triangle with area n.")