sjoin(v, j) := apply(sconcat, rest(join(makelist(j, length(v)), v)))$

display_pascal_triangle(n) := for i from 0 thru 6 do disp(sjoin(makelist(binomial(i, j), j, 0, i), " "));

display_pascal_triangle(6);
/* "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" */