Special factorials: Difference between revisions

add RPL
(add RPL)
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the inverse factorial of 3628800 is: 10
the inverse factorial of 119 is: undefined
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=={{header|RPL}}==
Super factorial:
≪ 1 1 ROT '''FOR''' j j FACT * '''NEXT'''
≫ '<span style="color:blue">SFACT</span>' STO
Hyper factorial:
≪ 1 1 ROT '''FOR''' j j DUP ^ * '''NEXT'''
≫ '<span style="color:blue">HFACT</span>' STO
Alternating factorial:
≪ → n
≪ 0 '''IF''' n '''THEN'''
1 n '''FOR''' j -1 n j - ^ j FACT * + '''NEXT'''
≫ ≫ '<span style="color:blue">AFACT</span>' STO
Exponential factorial:
≪ '''IF''' DUP '''THEN'''
DUP 1 - 1 '''FOR''' j j ^ -1 '''STEP'''
'''ELSE''' NOT '''END'''
≫ '<span style="color:blue">EFACT</span>' STO
Inverse factorial - this function actually inverses Gamma(x+1), so its result is always defined:
≪ 'FACT(x)' OVER - 'x' ROT LN ROOT 'x' PURGE
≫ '<span style="color:blue">IFACT</span>' STO
 
≪ { } 0 9 FOR j j <span style="color:blue">SFACT</span> + NEXT ≫ EVAL
≪ { } 0 9 FOR j j <span style="color:blue">HFACT</span> + NEXT ≫ EVAL
≪ { } 0 9 FOR j j <span style="color:blue">AFACT</span> + NEXT ≫ EVAL
≪ { } 0 4 FOR j j <span style="color:blue">EFACT</span> + NEXT ≫ EVAL
3628800 <span style="color:blue">IFACT</span>
119 <span style="color:blue">IFACT</span>
{{out}}
<pre>
6: { 1 1 2 12 288 34560 24883200 125411328000 5.05658474496E+15 1.83493347225E+21 }
5: { 1 1 4 108 27648 86400000 4.0310784E+12 3.31976639877E+18 5.56964379417E+25 2.15779412229E+34 }
4: { 0 1 1 5 19 101 619 4421 35899 326981 }
3: { 0 1 2 9 262144 }
2: 10
1: 4.99509387149
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