Catalan numbers: Difference between revisions

=={{header|RPL}}==

{{works with|Halcyon Calc|4.2.7}}

{| class="wikitable"

! Code

! Comments

|-

|

≪

'''IFERR''' R→B '''THEN END'''

'''IF''' DUP #1 ≠

'''THEN'''

DUP 2 * 1 - 2 * OVER 1 - →CAT * SWAP 1 + /

'''END'''

≫ ''''→CAT'''' STO

|

''( n -- C(n) )''

Ignore the conversion error if n is already a binary integer

C(1) = 1

Divide by (n+1) at the end to stay in the integer world

|}

To speed up execution, additions can be preferred to multiplications by replacing <code>2 *</code> with <code>DUP +</code>.

The following piece of code will deliver what is required:

≪ 1 { } '''DO''' OVER →CAT B→R + SWAP 1 + SWAP '''UNTIL''' OVER 15 > '''END''' ≫ EVAL

{{out}}

<pre>

1: { 1 2 5 14 42 132 429 1430 4862 16796 58786 208012 742900 2674440 9694845 }

</pre>