1.2. A Table of values of π(x)

njzz_yy

1 10 4   
2 100 25   
3 1,000 168   
4 10,000 1,229   
5 100,000 9,592   
6 1,000,000 78,498   
7 10,000,000 664,579   
8 100,000,000 5,761,455   
9 1,000,000,000 50,847,534   
10 10,000,000,000 455,052,511   
11 100,000,000,000 4,118,054,813   
12 1,000,000,000,000 37,607,912,018   
13 10,000,000,000,000 346,065,536,839   
14 100,000,000,000,000 3,204,941,750,802 [LMO85]
15 1,000,000,000,000,000 29,844,570,422,669 [LMO85]
16 10,000,000,000,000,000 279,238,341,033,925 [LMO85]
17 100,000,000,000,000,000 2,623,557,157,654,233 [DR96]
18 1,000,000,000,000,000,000 24,739,954,287,740,860 [DR96]
19 10,000,000,000,000,000,000 234,057,667,276,344,607   
20 100,000,000,000,000,000,000 2,220,819,602,560,918,840   
21 1,000,000,000,000,000,000,000 21,127,269,486,018,731,928   
22 10,000,000,000,000,000,000,000 201,467,286,689,315,906,290   
23 100,000,000,000,000,000,000,000 1,925,320,391,606,803,968,923   
24 1,000,000,000,000,000,000,000,000 18,435,599,767,349,200,867,866 (note)
25 10,000,000,000,000,000,000,000,000 176,846,309,399,143,769,411,680

lusishun

用公式p·连乘q/（q-1），
（其中q最小4，最大q+1=p，p为小于根号下n的最大素数），计算的数值，一定少于比n小的素数。
如n=100，则7·4/2·6/4=21，小于25.更精确的是不小于p至n的素数个数。

lusishun

订正：一定不少于比n小的素数个数。

lusishun

请教，若用n（1-1/2）（1-1/3）（1-1/5）……（1-1/p）计算的素数个数，是不是都比您给的值要小

wangyangke

定理：熊一兵作诗祝贺的的那个哥猜证明的证明人鲁思顺是个二百五。