10 REM Catalan numbers
20 DIM C(15)
30 LET C(0) = 1
40 PRINT 0, C(0)
50 FOR N = 0 TO 14
60 LET C(N+1) = 0
70 FOR I = 0 TO N
80 LET C(N+1) = C(N+1)+C(I)*C(N-I)
90 NEXT I
100 PRINT N+1, C(N+1)
110 NEXT N
120 END