ぃ琌计琾计

琾计

琾计 (Almost Prime) 琌计 (Composite Number) ┪计 (Prime Number)  (Prime Factor) (┪ぃ) 计单﹚计

Ω琾计 (2-almost Prime) 琌计ヘ 2 俱计 4 = 2*215 = 3*5111 = 3*372323 = 23*101 单常琌

Ω琾计 (2-almost Prime) 琌计ヘ 3 俱计 8 = 2*2*230 = 2*3*5105 = 3*5*7333 = 3*3*37 单常琌

痙種Ω琾计 (1-almost Prime) и竒盽弧计

琾计瞷﹍ǎ╯紈ぺ划瞦稱 (Goldbach Conjecture) 拜肈紈ぺ划瞦稱琌ぃぶ 6 案计 (Even Number) 糶Θㄢ计㎝и瓣计厩產 (Mathematician) 硂拜肈ǐ程玡ㄤい朝春柬 (Jingrun Chen 1933-1996) 皘矗の靡计糶Θ计のぃㄢ琾计㎝硂ョ琌и竒盽ē矗1+2癘├朝春柬癪膍嘿赣挡狦朝ん﹚瞶 (Chen's Theorem)

Ω琾计 (1-almost Prime)  23571113171923293137...... OEISA000040 虏癘 P
Ω琾计 (2-almost Prime)  469101415212225263334...... OEISA001358 虏癘 P2
Ω琾计 (3-almost Prime)  812182027283042444550...... OEISA014612 虏癘 P3
Ω琾计 (4-almost Prime)  1624364054566081848890...... OEISA014613 虏癘 P4
きΩ琾计 (5-almost Prime)  32487280108112120162168180...... OEISA014614 虏癘 P5

讽礛┮孔Ω琾计ㄤ龟獽琌и盽ǎ计τΩ琾计硂Ω会ネи穦嘿ㄤ计 (Semiprime) ┪计 (Biprime) 琌и竒盽钮ǎよ计 (Rectangle Number) и甧璶 k Ω琾计い计獽琌 k+1 Ω琾计タир甁┰Λ吹疭ェ縵猭 (Sieve of Eratosthenes)э碝т琾计ㄣよ猭琌玂痙 235硂ㄇ计ぃрㄤ计奔э奔 4610硂ㄇΩ琾计计獽穦逞Ω琾计摸崩

Ω琾计嘿计 (Triprime) ┪筏计 (Sphenic Number)摸崩ㄤ龟计┪计嘿㊣ぃ筁琌よ獽иτ

计

ㄤ龟穦瞷硈尿计 (Consecutive Semiprimes) ㎡氮琌穦 14 = 2 * 7 の 15 = 3 * 5 ┪ 33 = 3 * 11 34 = 2 * 17 の 35 = 5 * 7 单玌粂Τお碔ぃ筁硂计 (Sequence) ぃ筁计㎡–计ぇ丁羆Τ琌 4 计τ 4 セō沮ㄢㄤ计ぃ穦琌计程舱獽琌 33, 34, 35钡ㄓ临Τ 85, 86, 8793, 94, 95 141, 142, 143 单 (OEISA0039833)抖獽ēêΘ硈尿计獽琌 - 案 - Ω瞷τㄢ计いゲ礛Τ琌计獺ぃ獺パ

笵そΑ倒ぃぶ x 计计

Αい p(x) 计计ㄧ计 (Prime Counting Function)ぃ x 计计τ pk 材 k 计

Αパ E空焊 (E. Noel) ㎝猾隔吹 (G. Panos)  2005 る祇

瞷ㄇ盞衡猭 (Encryption Algorithm)  RSAそ芲盞絏(RSA Encryption Public-key Cryptograpy) 癸计惠―羭ㄇ耕疭獶キよ计

p * q 计 p 计 q 计
1048 + 19 49 21 28
1050 + 27 51 22 29
1053 + 63 54 25 29
1054 - 3 54 23 32
1055 - 9 55 25 31
1063 + 19 64 32 32

籔计闽笵螟肈

硂计嘿城ゅ吹计 (Jevons Number) 

8616460799 = 89681 * 96079

ㄓ硂计琌パ璣瓣竒蕾厩產城ゅ吹 (William Stanley Jevons 1835-1882) 矗弧拜肈τㄓτ城ゅ吹琌肈σ喷Τ⊿Τр硂计だ秆 1903 瓣计厩產DN筽纐 (Derrick Norman Lehmer 1867-1938) Θтだ秆Α

把σゅ膍の呼

Weisstein, E. M. "Almost Prime." From MathWorld. http://mathworld.wolfram.com/AlmostPrime.html.

Weisstein, E. M. "Jevons Number." From MathWorld. http://mathworld.wolfram.com/JevonsNumber.html.

Weisstein, E. M. "Semiprime." From MathWorld. http://mathworld.wolfram.com/Semiprime.html.