explore(n, s) = {
	my (p=1);
	forstep (k=n, 1, -1,
		p *= k;
		if (best < s+p && issquare(s+p),
			best = s+p;
		);
		if (s+p+(k-1)! > best,
			explore (k-1, s+p);
		);
	);

}

a(n) = {
	best = 0;
	explore(n, 0);
	return (sqrtint(best));
}

for (n=1, 39, print (n " " a(n)))

quit