What accounting entries are recorded for finance leases under the sum of digits method?

The sum of digits method is one of the accelerated depreciation method. You need to convert that into straight-line method, for the use of the installment amount.

Finance lease is also capital lease. Here is the entries:

When asset is leased,
Dr Leased equipment xxx
Cr Lease obligation xxx

To depreciate asset,
Dr Depreciation xxx
Cr Accumulated depn xxx

To record instalment payment,
Dr Interest expense xxx
Dr Lease obligation xxx
Cr Cash xxx