In Google Sheets, I'd like to use something like arrayformula() to apply a formula to an entire 2-dimensional array, where the arguments of the formula are taken from the row/column headers.
Example here. So something like arrayformula(B1:F1&A2:A10). I know I could write =B$1&$A2 into the top left and then copy it across, but I'm wondering if it's possible to remove the need to copy and paste.