On a ratio between relative class numbers.
Let be the set of positive integers and let . We denote by the arithmetic function given by , where is the number of positive divisors of . Moreover, for every we denote by the sequence We present classical and nonclassical notes on the sequence , where , , are understood as parameters.
Let be the set of prime numbers (or more generally a set of pairwise co-prime elements). Let us denote , where . Then for arbitrary finite set , holds and If we denote where is the set of all prime numbers, then for closure of set holds where .