Iterated stable number and amicable pairs derived from restricted divisor functions and matrix

Daeyeoul Kim (Jeonbuk National University) 

October  13 (Fri)  2023, 10시 20분 ~ 11시 20분  아산이학관 526호

Abstract: The results of this talk are elementary. It can be seen that various values can be obtained by iterating the restricted divisor functions and matrix. If we consider iteration of t-free divisor functions, then the values of them sees four cases, that is, stable, amicable pair, sociable,  unpredictable sequences. 

Quadratic forms with a stong regularity

Kyoungmin Kim  (Hannam University)

October  13 (Fri)  2023, 11시 40분 ~ 12시 40분  아산이학관 526호

Abstract:  A (positive definite and non-classic integral) quadratic form is called strongly s-regular if it satisfies a strong regularity property on the number of representations of squares of integers. In this talk, we show that for any integer k ě 2, there are only finitely many isometry classes of strongly s-regular quadratic forms with rank k if the minimum of the nonzero squares that are represented by them is fixed.