Sure, what's your question? I spent part of today making some for my church auction. Sorry I misread your question. I don't have a pattern but I don't think you need one.
You need 5 five-inch squares. You press 4 of them in half diagonally so they look like half-square triangles. You place your un folded square right side up. Next take your first folded square and line up the raw edges to the ones on the square. Rotate your coaster 1/4 turn and line up the next "half square triangle' in the same way; do that 3 times. For the 4th and last HST, line up the first corner as you did the other 3 and then tuck in your last corner under the FIRST HST you place. Pin it all together and sew it. Trim your corners and your seams then turn right side out. I press mine to make them look more finished. I hope this makes sense. PM me if it doesn't.