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+--- Thread: (33s): OEIS A8905 & A34886: 1st Digit of N! & Number of Digits in N! (/thread-18585.html)
(33s): OEIS A8905 & A34886: 1st Digit of N! & Number of Digits in N! - Gerald H - 07-23-2022 02:07 PM
[Edit 2022-07-24: Programmes W & X corrected.]
The 33s has both RPN & Algebraic capabilities, exemplified by the two programmes below.
The RPN version uses up two of the scarce LBLs & occupies 174 Bytes of the ample memory.
The Algebraic version requires 144 Bytes of memory.
The RPN version is faster.
Most of my students find the Algebraic version much clearer & easier to programme.
Takes a real integer N from the stack & returns A8905(N) & A34886(N) to stack.
First digit of n!; Number of digits in n!.
https://oeis.org/A008905
https://oeis.org/A034886
Code:
1. LBL S
2. 3
3. x<y?
4. GTO T
5. R↓
6. x!
7. 1
8. RTN
1. LBL T
2. R↓
3. ENTER
4. LOG
5. ENTER
6. ENTER
7. 1
8. e^x
9. LOG
10. –
11. R↑
12. *
13. x<>y
14. π
15. ENTER
16. +
17. LOG
18. +
19. 2
20. /
21. +
22. ENTER
23. FP
24. 10^x
25. IP
26. x<>y
27. IP
28. 1
29. +
30. RTNAlternative to programme S.
Code:
1. LBL W
2. 3
3. x<y?
4. GTO X
5. R↓
6. x!
7. 1
8. RTN
1. LBL X
2. R↓
3. STO N
4. CLx
5. 1+(LOG(2)+LOG(π)+LOG(N))/2+N*(LOG(N)-LOG(EXP(1)))
6. STO N
7. IP(ALOG(FP(N)))
8. IP(N)
9. RTNRE: (33s): OEIS A8905 & A34886: 1st Digit of N! & Number of Digits in N! - Gerald H - 07-24-2022 09:41 AM
Edit to post #1, programmes W & X corrected.