Half-precision Γ(x+1) [HP-12C]

[Gerson W. Barbosa]

41 steps on my HP-41C (but you can always make it shorter).

01 LBL "GXP1"
02 ENTER
03 ENTER
04 336
05 *
06 224
07 +
08 X<>Y
09 *
10 99
11 ST+ Y
12 X<> L
13 ENTER
14 ENTER
15 56
16 *
17 42
18 +
19 X<>Y
20 *
21 18
22 ST+ Y
23 X<> L
24 X<> Z
25 /
26 X<>Y
27 +
28 ST+ X
29 LASTX
30 RCL X
31 -1
32 E^X
33 *
34 X<>Y
35 Y^X
36 X<>Y
37 PI
38 *
39 SQRT
40 *
41 END



.5-> 0.8862(859731)
1 -> 1.00000(8281)
2 -> 2.00000(1930)
3 -> 6.000000(983)
4 -> 24.000000(68)
5 -> 120.0000000
6 -> 719.9999952 (720)
7 -> 5039.999965 (5040)
8 -> 40319.99985 (40320)
9 -> 362879.9989 (362880)
10-> 3628799.990 (3628800)
11-> 39916799.89 (39916800)
12-> 479001598.8 (479001600)
13-> 6227020801 (6227020800)
14-> 871782912(1)E10
15-> 1.307674368E12
20-> 2.4329020(11)E18
50-> 3.0414093(32)E64
60-> 8.3209871(07)E81
69-> 1.71122452(1)E98
69.95 -> 9.68284767(8)E99

P.S.:

37 steps

01 LBL "GXP1"
02 ENTER
03 ENTER
04 +
05 RCL X
06 1.5
07 +
08 6
09 X<>Y
10 /
11 CHS
12 7
13 +
14 6
15 X<>Y
16 /
17 +
18 1/X
19 CHS
20 6
21 +
22 1/X
23 +
24 ST+ X
25 X<>Y
26 R^
27 -1
28 E^X
29 *
30 X<>Y
31 Y^X
32 X<>Y
33 PI
34 *
35 SQRT
36 *
37 END