Gourt > Science > Math > Number Theory > Factoring > Perfect Numbers
In mathematics, a perfect number is defined as an integer which is the sum of its proper positive divisors, that is, the sum of the positive divisors not including the number. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors, or σ(n) = 2 n.
Six (6) is the first perfect number, because 1, 2 and 3 are its proper positive divisors and 1 + 2 + 3 = 6. The next perfect number is 28 = 1 + 2 + 4 + 7 + 14. The next perfect numbers are 496 and 8128 .
These first four perfect numbers were the only ones known to the ancient Greeks.
More on [ Perfect number ]
Does Your Love Life Add Up?: How to Use Numbers to Find Your Perfect Relationship - by Max Coppa - Tarcher. http://bit.ly/6839G7
nonfiction_book (New Nonfiction Books) Fri, 25 Dec 2009 02:11:50 -0000
Does Your Love Life Add Up?: How to Use Numbers to Find Your Perfect Relationship - by Max Coppa - Tarcher. http://bit.ly/6839G7
Does Your Love Life Add Up?: How to Use Numbers to Find Your Perfect Relationship - by Max Coppa - Tarcher. http://bit.ly/7z3m56
health_book (New Health Books) Thu, 24 Dec 2009 22:15:10 -0000
Does Your Love Life Add Up?: How to Use Numbers to Find Your Perfect Relationship - by Max Coppa - Tarcher. http://bit.ly/7z3m56
Does Your Love Life Add Up?: How to Use Numbers to Find Your Perfect Relationship - by Max Coppa - Tarcher. http://bit.ly/4FikrW
religion_book (New Religion Books) Thu, 24 Dec 2009 19:00:10 -0000
Does Your Love Life Add Up?: How to Use Numbers to Find Your Perfect Relationship - by Max Coppa - Tarcher. http://bit.ly/4FikrW
The look on the face of the micromanaging CEO's when the replenishment numbers are within 0.07% of perfect. Priceless. Nothing for him to do
jeremykatg (Jeremy ) Thu, 24 Dec 2009 15:34:39 -0000
The look on the face of the micromanaging CEO's when the replenishment numbers are within 0.07% of perfect. Priceless. Nothing for him to do
love's like a rubiks cube, there're countless numbers of wrong and turns,but when it right, looks perfect no matter what way u look at it
ladylaras (b. indah larasati) Thu, 24 Dec 2009 07:04:58 -0000
love's like a rubiks cube, there're countless numbers of wrong and turns,but when it right, looks perfect no matter what way u look at it
@dumdidav @e_ting I didn't know there was an "official" Christmas dinner bird. Goose is perfect for smaller numbers.
niltiac (Caitlin Fitzsimmons) Wed, 23 Dec 2009 23:49:57 -0000
@dumdidav @e_ting I didn't know there was an "official" Christmas dinner bird. Goose is perfect for smaller numbers.
Aliquot - Sequences with initial term up to 10,000, by Christophe Clavier.
Aliquot Sequences - Juan L. Varona's work on aliquot sequences examines sequences with start values up to 10000, and traces them to large composite values.
Aliquot Sequences - Results and software from Paul Zimmermann, addressing the Catalan Conjecture and working on the difficult Lehmer Five sequences.
Aliquot Sequences - Aliquot sequences arise in iterating the sum-of-divisors function s. Bosma has calculated tables up to start value 50,000 and 80 digits.
Aliquot Sequences - Statistics by Wolfgang Creyaufmueller, including many tables and links to factoring sites and software.
Meta Description: [ To proof Catalans conjecture needs many aliquot sequences.
The programmes (download) factorize up to 120 digits. ]
Amicable Numbers - Observations on amicable pairs and their distribution, including Harshad and Happy Amicable pairs.
Cubes of Perfection - From Ivars Peterson's MathTrek column in MAA Online. Curious relationships satisfied by perfect numbers.
Multiply Perfect Numbers - Up-to-date information on multiperfect numbers and searchable database maintained by Achim Flammenkamp.
Odd Perfect Numbers - Missing Values - Status of various factorisations that would extend the known area of non-existence of odd perfect numbers, by Kevin Hare.
Perfect Number - from MathWorld - Definitions and references.
Perfect Numbers - A detailed history of the quest for perfect numbers, from Euclid to their present-day Mersenne discoveries.
Tables of Aliquot Cycles - Data for various kinds up to 10^12, including unitary, infinitary, exponential, augmented and reduced varieties.
404
The Perfect Number Journey - A Mathematics Enrichment Workshop introducing perfect numbers. Lessons and exercises extend over several pages. Aimed at interested middle and high school students.
| Winx Club Season 4 | |
| Next Video | |
