Make your program sequential!

Python 2, 35 Bytes

I decided to use the obvious sequence A000027, which essentially has the formula n ;) If you run the following code:

#print'n'
n=1
exec'print n;n+=1;'*8

You get the output:

1
2
3
4
5
6
7
8

And if you take the 8 characters from my source code (0-indexed), you get this:

print'n'

Which simply prints n.

---

If you were hoping for a more exciting answer, here's a Python 2 solution for n^2, i.e. A000290:

#p  r    i      n        t          '            n              ^                2                  '
n=1
exec'print n*n;n+=1;'*10

05AB1E, 7 6 bytes, A000027

5L'n s

Try it online!

Explanation:

5L      # Push [1, 2, 3, 4, 5]
  'n    # Push "n"
        # Do nothing
     s  # Swap (only in original program)
        # Implicit print

Octave, 64 bytes A000290

I went for the n^2 one:

@()(1:5 ).^2 % '        n          ^            2              '

Take the terms 1, 4, 9, 16, 25, 36, 49 and 64 to get:

@()'n^2'

which prints:

n^2