This problem has been driving me crazy:

Specify each sequence both explicitly and recursively. (Hint: For the recursive rule, consider a(subscript: n+1) - a(subscript: n)

1, 4, 9, 16, 25...

I need help on what they mean by a(subscript: n+1) - a(subscript: n). I know it has something to do with moving a(subscript: n) over in the recursive rule equation (a[subscript: n+1] = a[subscript: n] + D where D is the common difference) but I can't figure it out...