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Unusual Number
In number theory, an unusual number is a natural number ''n'' whose largest prime factor is strictly greater than \sqrt. A ''k''-smooth number has all its prime factors less than or equal to ''k'', therefore, an unusual number is non-\sqrt-smooth. Relation to prime numbers All prime numbers are unusual. For any prime ''p'', its multiples less than ''p''2 are unusual, that is ''p'', ... (''p''-1)''p'', which have a density 1/''p'' in the interval (''p'', ''p''2). Examples The first few unusual numbers are : 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 20, 21, 22, 23, 26, 28, 29, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 46, 47, 51, 52, 53, 55, 57, 58, 59, 61, 62, 65, 66, 67, ... The first few non-prime (composite) unusual numbers are : 6, 10, 14, 15, 20, 21, 22, 26, 28, 33, 34, 35, 38, 39, 42, 44, 46, 51, 52, 55, 57, 58, 62, 65, 66, 68, 69, 74, 76, 77, 78, 82, 85, 86, 87, 88, 91, 92, 93, 94, 95, 99, 102, ... Distribution If we denote the number of unusual numbers less than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unusual Number Cuisenaire Rods 10
Unusual or The Unusual or The Unusuals may refer to: Film and TV *''The Unusuals'', a 2009 TV series. Music *''The Unusual'', an El Da Sensei album *Unusual (album) Giuni Russo 2006 Songs *Unusual (song) Trey Songz *"Unusual", song by Francesca Battistelli from ''If We're Honest'' *"Unusual" ( fa, غیر معمولی), song by Mohsen Chavoshi See also *Anomaly (other) *Wikipedia:Unusual articles *:Lists of things considered unusual {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
