mata
function pascal1(n) {
	return(comb(J(1,n,0::n-1),J(n,1,0..n-1)))
}

function pascal2(n) {
	a = I(n)
	a[.,1] = J(n,1,1)
	for (i=3; i<=n; i++) {
		a[i,2..i-1] = a[i-1,2..i-1]+a[i-1,1..i-2]
	}
	return(a)
}

function pascal3(n) {
	a = J(n,n,0)
	for (i=1; i<n; i++) {
		a[i+1,i] = i
	}
	s = p = I(n)
	k = 1
	for (i=0; i<n; i++) {
		p = p*a/k++
		s = s+p
	}
	return(s)
}
end