Filing return for deceased son. All 2016 income is from retirement & Pension plans. I am executor & beneficiary. Do I file 1040 for him or add beneficiary income to mine?

K-1 needed with Form 1041.
One post implies I can do a 1040 & Estate return but is that for son's 1040 or mine if beneficiary income is reported by me.
An answer with ref to IRS docs would be appreciated.