5 minute Erlang version: -module(pascal). -export([tri/1]). tri(Depth) -> tri(Depth,[[1]]). calc_row_rest([_]) -> [1]; calc_row_rest([X,Y |

5 minute Erlang version: -module(pascal). -export([tri/1]). tri(Depth) -> tri(Depth,[[1]]). calc_row_rest([_]) -> [1]; calc_row_rest([X,Y | Rest]) -> [X + Y | calc_row_rest([Y | Rest])]. calc_row(Acc) -> [1 | calc_row_rest(Acc)]. tri(X,_) when X =< 0 -> []; tri(1,Acc) -> lists:reverse(Acc); tri(Depth,Acc) -> NewRow = calc_row(hd(Acc)), tri(Depth-1,[NewRow | Acc]). Returns a list of the pascal triangle rows: > pascal:tri(10). [[1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1], [1,5,10,10,5,1], [1,6,15,20,15,6,1], [1,7,21,35,35,21,7,1], [1,8,28,56,70,56,28,8,1], [1,9,36,84,126,126,84,36,9,1]]