Calkin-Wilf sequence: Difference between revisions

=={{header|RPL}}==

{{works with|HP|49g}}

≪ { } SWAP

'''WHILE''' DUP '''REPEAT '''

ROT OVER IDIV2

4 ROLL ROT + SWAP

'''END''' ROT DROP2

≫ '<span style="color:blue">CONTFRAC</span>' STO

≪ {1}

'''WHILE''' DUP2 SIZE > '''REPEAT'''

DUP DUP SIZE GET

DUP IP R→I 2 * 1 + SWAP - INV EVAL +

'''END''' NIP

≫ ≫ '<span style="color:blue">CWILF</span>' STO

≪

<span style="color:blue">CONTFRAC</span> DUP SIZE

'''IF''' DUP MOD '''THEN''' DROP '''ELSE'''

DUP2 GET 1 - PUT 1 + '''END'''

1 → frac pow2

≪ 0

1 frac SIZE '''FOR''' j

frac j GET

'''WHILE''' DUP '''REPEAT'''

'''IF''' j 2 MOD '''THEN''' SWAP pow2 + SWAP '''END'''

2 'pow2' STO*

1 -

'''END''' DROP

'''NEXT'''

≫ ≫ '<span style="color:blue">CWPOS</span>' STO

20 <span style="color:blue">CWILF</span>

83116 51639 <span style="color:blue">CWPOS</span>

{{out}}

<pre>

2: {1 '1/2' 2 '1/3' '3/2' '2/3' 3 '1/4' '4/3' '3/5' '5/2' '2/5' '5/3' '3/4' 4 '1/5' '5/4' '4/7' '7/3' '3/8'}

1: 123456789

</pre>