Now I understand your concern. Section 408(d)(8)(A)(i) of the tax code says that in and after the year the taxpayer reaches age 70½, "deductions allowed to the taxpayer under section 219" of the tax code reduce the amount of QCDs that are excludible from income. The deduction for those contributions is reported on Schedule 1 line 20. SEP contributions are not such contributions. SEP contributions are employer contributions (even for the self-employed).
Some SEP IRA custodians allow regular traditional IRA contributions to be made to SEP IRAs and those would be the same as if they were made to the regular traditional IRA, deductible on Schedule 1 line 20. It's generally recommended that one not make regular traditional IRA contributions to a SEP IRA due to the potential for the IRA custodian to confuse these for SEP contributions.
