c# loops, printing number patterns

Question

program should print

1

2 1

3 3 1

4 6 4 1 

and then should ask for input from user and then it should print the sum of the elements in that row

if we enter 1

then it should return 1

if we enter 2

then it should return 2+1 i.e. 3

for 3

3+3+1 i.e. 9..