| 翻訳と辞書 |
| deficient number ： ウィキペディア英語版 |
deficient number
In number theory, a deficient or deficient number is a number ''n'' for which the sum of divisors ''σ''(''n'')<2''n'', or, equivalently, the sum of proper divisors (or aliquot sum) ''s''(''n'')<''n''. The value 2''n'' − ''σ''(''n'') (or ''n'' − ''s''(''n'')) is called the number's deficiency.
==Examples==
The first few deficient numbers are:
:1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 22, 23, 25, 26, 27, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, ...
As an example, consider the number 21. Its divisors are 1, 3, 7 and 21, and their sum is 32. Because 32 is less than 2 × 21, the number 21 is deficient. Its deficiency is 2 × 21 − 32 = 10.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「deficient number」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|