n=5

A=ones(2*n,n)

A =

     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1

Q=[1:n;ones(n-1,n)];
P=cumsum(Q)

P =

     1     2     3     4     5
     2     3     4     5     6
     3     4     5     6     7
     4     5     6     7     8
     5     6     7     8     9

A(1:2:end,:)=P

A =

     1     2     3     4     5
     1     1     1     1     1
     2     3     4     5     6
     1     1     1     1     1
     3     4     5     6     7
     1     1     1     1     1
     4     5     6     7     8
     1     1     1     1     1
     5     6     7     8     9
     1     1     1     1     1

x=2:(n+1)

x =

     2     3     4     5     6

x=fliplr(x)

x =

     6     5     4     3     2


X=[x;ones(n-1,n)]

X =

     6     5     4     3     2
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1
     1     1     1     1     1

Y=cumsum(X)

Y =

     6     5     4     3     2
     7     6     5     4     3
     8     7     6     5     4
     9     8     7     6     5
    10     9     8     7     6

format rat

Z=1./Y

Z =

       1/6            1/5            1/4            1/3            1/2     
       1/7            1/6            1/5            1/4            1/3     
       1/8            1/7            1/6            1/5            1/4     
       1/9            1/8            1/7            1/6            1/5     
       1/10           1/9            1/8            1/7            1/6     

A(2:2:end,:)=Z

A =

       1              2              3              4              5       
       1/6            1/5            1/4            1/3            1/2     
       2              3              4              5              6       
       1/7            1/6            1/5            1/4            1/3     
       3              4              5              6              7       
       1/8            1/7            1/6            1/5            1/4     
       4              5              6              7              8       
       1/9            1/8            1/7            1/6            1/5     
       5              6              7              8              9       
       1/10           1/9            1/8            1/7            1/6     

diary off