Why Even Almost Perfect Number should not be Divisible by 3? A non-Almost Perfect Criterion for Even Positive Integers n ≠ 2k

被引:0
|
作者
Antalan, John Rafael M. [1 ]
机构
[1] Cent Luzon State Univ, Dept Math & Phys, Coll Arts & Sci, Sci City Of Munoz 3120, Nueva Ecija, Philippines
关键词
Almost Perfect Number; Sum of divisors; Sum of divisor function of a positive integer n sigma(n); abundancy index of a positive integer n I(n);
D O I
10.1063/1.4882588
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
Two of the oldest open problems in elementary number theory are (1) to find a quasi-perfect number and (2) to show that only numbers of the form 2(k), k is an element of Z(+) are almost perfect. A positive integer is quasi perfect if the sum of its positive divisors sigma(n) is equal to 2n + 1 where as n is almost perfect if sigma(n) is equal to2n - 1.In 1951, Cattaneo showed that quasi perfect numbers cannot be even. Recently, Antalan (2013) showed that almost perfect numbers not of the form 2(k) must be of the form 2(x)b(2) where x is an element of Z(>= 0) and b is an odd composite positive integer. Here we give sufficient non - almost perfect criterion for even positive integers n(e) of the form 2(x)b(2). Particularly we show that n(e) is automatically not an almost perfect number if it is divisible by 2(x) and a prime <= 2(x+1) - 1. Lastly we state a problem on almost perfect numbers related to what Cattaneo did on quasi perfect number.
引用
收藏
页码:881 / 885
页数:5
相关论文
empty
未找到相关数据