HP 9g User Manual page 78

When the message " 1: A(N), 2 :S(N) " appears on the display, you can
input a " P " value to specify the type of operation to be
performed:
1 for A(N)
(1) A = 5 , R = 4, N = 7
[ ] ( 5 Seconds )
1 [ ] 5 [
4 [ ] 7
RUN
A (N) = A (7) = 20480
]
E-78
2 for S(N)