I recently installed a used Hampton Bay ceiling fan and cannot find replacement bulbs standard base too large for socket candelier base too small for socket
Inside the socket reads E307185 40 watt Home Depot which sells fan was not helpful

Those are intermediate size bulbs. E17. However, they are readily available on the internet and they sell adapters to convert from intermediate to chandelier size. Check with Lowe's, I believe I have seen them there.