b = vector(20 100)		\\ inverse of a
x = vector(#b, i, i)	\\ product of ancestors of n

uo = 1	\\ least unseen odd

other(n) =										\
	my (o=n);									\
	while (b[o]>1, o=b[o]);						\
	my (v=uo);									\
	while (b[v] || gcd(x[o], v)>1, v+=2);	\
	return (v)

{
	for (n=1, 10 000,
		a = other(n);
		b[a] = n;

		while (b[uo], uo += 2);

		o = a;
		while (b[o]>1, o = b[o]);
		x[o] *= a;

		print (n " " a);
	)
}

quit