16 lines
528 B
Text
16 lines
528 B
Text
nextrow[lastrow_] := Module[{output},
|
|
output = ConstantArray[1, Length[lastrow] + 1];
|
|
Do[
|
|
output[[i + 1]] = lastrow[[i]] + lastrow[[i + 1]];
|
|
, {i, 1, Length[lastrow] - 1}];
|
|
output
|
|
]
|
|
pascaltriangle[size_] := NestList[nextrow, {1}, size]
|
|
catalannumbers[length_] := Module[{output, basetriangle},
|
|
basetriangle = pascaltriangle[2 length];
|
|
list1 = basetriangle[[# *2 + 1, # + 1]] & /@ Range[length];
|
|
list2 = basetriangle[[# *2 + 1, # + 2]] & /@ Range[length];
|
|
list1 - list2
|
|
]
|
|
(* testing *)
|
|
catalannumbers[15]
|