Series would be like: 1, 4, 14, 45, 139.

It is like that:

1,

4 [(1*3) + 1]

14 [(4*3) + 2]

45 [(14*3)+3]

139 [(45*3)+4]

Logic: You need to a Multiply the previous number with three and add

the digit that comes next to previously added number as shown above.

It is like that:

1,

4 [(1*3) + 1]

14 [(4*3) + 2]

45 [(14*3)+3]

139 [(45*3)+4]

Logic: You need to a Multiply the previous number with three and add

the digit that comes next to previously added number as shown above.