Entity FrameWork Query

For My  Entity FrameWork, in the For Loop

While working Evaluating, serial number 4 5 and 6

I should get the previous Tansaction(Transaction Sequence - 1) row

Ex: for SerialNumber 4, the previuos transaction is 1, same way for 5 its 2 and for 6 its 3

I tried below, it did not work

var previousTransactions = transactions
    .Where(pt => pt.Check_Number == t. Check_Number
    //&& pt.Check_Version == t. pt.Check_Version
    && pt.Transaction_Sequence == Transaction_Sequence).FirstOrDefault();
    //.OrderByDescending(pt => pt.Sequence_Number).FirstOrDefault());
    .Distinct(new TransactionComparer());
}