Are employer contributions to a solo 401k completely deductible? And for a sole proprietor are employee and employer contributions all deducted?

For example, if I am a sole prop with no employees and earn $100k this year, I can: Contribute $17k to solo 401k as an employee Contribute $20k to solo 401k as an employer (~20% of $100k) And then deduct $37k on my taxes on line 28 of the 1040?