This is finance mathematics, not really accounting calculation.
$a = present value of one dollar paid per period,
for the term of n years, this PV is called annuity = (1- v^n)/i, for payment and the end of each period.
With i = 0.0661, v = 1/(1+0.0661), n = 30,
Then
$a * P = $375,000
solve equation, you get P, which is the yearly repayment.
if you use n = 30 *12, i = 1.0661 ^(1/12) -1, use this i for a new v.
you will get P for monthly repayment.
So on, use the period of 52.25, you can get weekly repayment.
You can refer to Excel PV function.
