I believe just one.....there are two instances of 43 in (wait for it)....Row 43 !!!
Note that 43 does not appear in any of the first 9 rows
And in Row 10 ....C(10,2) = 45.... and this is the smallest number in the triangle from this point forward [ except for the elements C(n,0), C(n,1), C(n-1, n), C (n, n) ] that appear on each row from row 11 to row 42.....all these elements will be < 43......and 43 will not appear in any row after row 43