RosettaCodeData/Task/Catalan-numbers/Factor/catalan-numbers.factor
Ingy döt Net b83f433714 tasks a-s
2013-04-10 23:57:08 -07:00

23 lines
300 B
Factor

: next ( seq -- newseq )
[ ] [ last ] [ length ] tri
[ 2 * 1 - 2 * ] [ 1 + ] bi /
* suffix ;
: Catalan ( n -- seq ) V{ 1 } swap 1 - [ next ] times ;
15 Catalan .
V{
1
1
2
5
14
42
132
429
1430
4862
16796
58786
208012
742900
2674440
}