If as an unincorporated self-employed person, one contributed
- x dollars to my individual 401(k) personally
- y dollars to my individual 401(k) as my own employer
How are these two numbers reflected on a standard (2014) 1040 tax forms? Schedule C?
You report all of your own contributions on line 28 of the Form 1040, you report the matching to your employees (if you have any) on line 19 (pensions and profit sharing plans) of your Schedule C.
Deducting your own contributions on Schedule C is not allowed because it affects the SE tax calculation (the 401(k) contributions are not exempt from FICA/SE taxes).
IRS has a nice page with examples on how to calculate the amounts.