HP 33s - Manual (Page 291)

Miscellaneous Programs and Equations 17–9
Program Lines:
(In ALG mode)
Description
%

 
%
 º
>¸@ Tests to see whether all possible factors have been tried.
%
 ! & If all factors have been tried, branches to the display
routine.
%
  Calculates the next possible factor, D + 2.
%
 ! - 
%
 ! % Branches to test potential prime with new factor.
Checksum and length: 161E 57
Flags Used:
None.
Program Instructions:
1. Key in the program routines; press ‡ when done.
2. Key in a positive integer greater than 3.
3. Press X P to run program. Prime number, P will be displayed.
4. To see the next prime number, press g .
Variables Used:
P Prime value and potential prime values.
D Divisor used to test the current value of P.
Remarks:
No test is made to ensure that the input is greater than 3.
Example:
What is the first prime number after 789? What is the next prime number?