write (*,*) 
     *' put # of nodes and aver degree in two comma-separated columns'
      write (*,*) 
     *' of a file named coef.txt & coef.out will compute the Bollobasi'
      write (*,*) 
     *' and Riordan (2003) expected value of the clustering coefficient'
      write (*,*) 
     *' for a scale-free network with these parameters'
      pause
      open (1,file='coef.txt')
      open (2,file='coef.out')
      do i=1,100
      read (1,*,end=1,err=2) a, b
      c=((b-1)*(log10(a)**2))/(8*a)
      write (*,'(F20.0,F7.1,f15.10)') a, b, c
      write (2,'(F20.0,F7.1,f15.10)') a, b, c
      enddo
2     write (*,*) ' error in coef.txt file'
      stop
1     write (*,*) 
     *' Number of Nodes   Aver Degree     Expected Clustering'
      write (2,*) 
     *' Number of Nodes   Aver Degree     Expected Clustering'
      end