\\ Helper function
isquadro(k,n) =
{
  local(i1);

  i1=isprime(2^n-k);
  i1+=isprime(2^n+k);
  i1+=isprime(k*2^n+1);
  i1+=isprime(k*2^n-1);

  return(i1);
}

\\ Verify whether (k,n) is DodecaProth
\\ Set v=0 to suppress text output.
isddp(k,n,v=1) =
{
  local(i2, i3);

  \\ Is DodecaProth ?
  i2=isquadro(k,n);
  i2+=isquadro(k,n+1);
  i2+=isquadro(k,n+2);
  if(i2==12,
    if(v, print1(k," ",n," is DodecaProth!")),
    return(0);
  );

  \\ Count legs
  if(v,
    i2=isquadro(k,n-1);
    i3=isquadro(k,n+3);
    print(" ... Left_legs=", i2, ", Rigth_legs=", i3,".");
  );

  return(1);
}