I read the 2-4-1 article in the top questions but I'm still confused. We will be in London for eight nights. As I understand it, you have to buy a travelcard from an overground station to be eligible for the 2-4-1 BUT you can't buy a 7d travelcard because its on an Oyster when bought over ground... can you buy a 7 day travelcard underground and have it work?
Is there any option other than buying 7 individual travelcards to use the 2-4-1 deal?
Is there a link where I can find the prices for the week long travelcards, just so I can compare the price difference between 7 individual days and a week long card?