Nano.mapping of the analogue pins

Normally the analogue pins A0 - A5 are mapped as D14 - D19

What is the mapping for A7 and A8 on the Nano????

(I have tried D20 and D21 but they are not working as digital pins)

A6 and A7 are not usable as digital i/o pins, only as analog inputs. This is a limitation of the ATmega microcontroller.