backwards(n) = fromdigits(Vecrev(digits(n)))
nextcompo(n) = while (isprime(n), n++); n

p(n) = backwards(nextprime(n+1))
c(n) = backwards(nextcompo(n+1))

{
	C = [2];
	while (1,
		CC = setunion(C, setunion(Set(apply(e -> c(c(e)), C)),
		                          Set(apply(e -> c(p(e)), C))));
		if (C!=CC,
			C = CC,
			apply (e -> print (n++ " " e), C);
			break;
		);
	);

	print ("# max(C) = " vecmax(C));
	print ("# max({c(k), k in C}) = " vecmax(apply(c, C)));
	print ("# max({p(k), k in C}) = " vecmax(apply(p, C)));
}

quit