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哈-李公式计算,在偶数比较小的范围内也是有正误差的,但是平均相对误差值为负值;至于从偶数多少大起没有正误差,没有核实过。
连乘式的计算值,在小偶数范围,是比较贴近素对真值的变化的;
因为随偶数增大后相对误差均值会逐渐偏离0位趋向0.21附近,因此大偶数必须增加一个修正系数,才能比较精确的计算出素对数量的计算值;
若要始终得到的素对计算值是下界值,不大于真值,则也必须增加一个修正系数。
inf( M ) = 1/(1+ .21 )*( M /2 -2)*p(m) ;(适用于 M≥6 的任意偶数)
式中的p(m)即为连乘式。
举例:1000亿起的连续偶数的素对下界值的计算:
G(100000000000) = 149091160;
inf( 100000000000 )≈ 142957976.6 , Δ≈-0.041137 ,infS( 100000000000 )= 107218482.41 , k(m)= 1.33333
G(100000000002) = 268556111;
inf( 100000000002 )≈ 257491343.1 , Δ≈-0.041201,infS( 100000000002 )= 107218482.41 , k(m)= 2.40156
G(100000000004) = 111836359;
inf( 100000000004 )≈ 107224584.4 , Δ≈-0.041239,infS( 100000000004 )= 107218482.41 , k(m)= 1.00006
G(100000000006) = 111843604;
inf( 100000000006 )≈ 107245660.7 , Δ≈-0.041110,infS( 100000000006 )= 107218482.42 , k(m)= 1.00025
G(100000000008) = 223655943;
inf( 100000000008 )≈ 214436964.8 , Δ≈-0.041219,infS( 100000000008 )= 107218482.42 , k(m)= 2
G(100000000010) = 150645060;
inf( 100000000010 )≈ 144447965.8 , Δ≈-0.041137,infS( 100000000010 )= 107218482.42 , k(m)= 1.34723
G(100000000012) = 128533939;
inf( 100000000012 )≈ 123239635.0 , Δ≈-0.041190,infS( 100000000012 )= 107218482.42 , k(m)= 1.14943
G(100000000014) = 238586864;
inf( 100000000014 )≈ 228760131.1 , Δ≈-0.041187,infS( 100000000014 )= 107218482.42 , k(m)= 2.13359
G(100000000016) = 134188011;
inf( 100000000016 )≈ 128662178.9 , Δ≈-0.041180,infS( 100000000016 )= 107218482.43 , k(m)= 1.2
G(100000000018) = 111942653;
inf( 100000000018 )≈ 107340460.2 , Δ≈-0.041112,infS( 100000000018 )= 107218482.43 , k(m)= 1.00114
G(100000000020) = 298192310
inf( 100000000020 )≈ 285915953.2 , Δ≈-0.041169,infS( 100000000020 )= 107218482.43 , k(m)= 2.66667
G(100000000022) = 124402721;
inf( 100000000022 )≈ 119283555.6 , Δ≈-0.041150,infS( 100000000022 )= 107218482.43 , k(m)= 1.11253
inf( 100000000000 ) = 1/(1+ .21 )*( 100000000000 /2 -2)*p(m) ≈ 142957976.6 , k(m)= 1.33333
inf( 100000000002 ) = 1/(1+ .21 )*( 100000000002 /2 -2)*p(m) ≈ 257491343.1 , k(m)= 2.40156
inf( 100000000004 ) = 1/(1+ .21 )*( 100000000004 /2 -2)*p(m) ≈ 107224584.4 , k(m)= 1.00006
inf( 100000000006 ) = 1/(1+ .21 )*( 100000000006 /2 -2)*p(m) ≈ 107245660.7 , k(m)= 1.00025
inf( 100000000008 ) = 1/(1+ .21 )*( 100000000008 /2 -2)*p(m) ≈ 214436964.8 , k(m)= 2
inf( 100000000010 ) = 1/(1+ .21 )*( 100000000010 /2 -2)*p(m) ≈ 144447965.8 , k(m)= 1.34723
inf( 100000000012 ) = 1/(1+ .21 )*( 100000000012 /2 -2)*p(m) ≈ 123239635 , k(m)= 1.14943
可以看到,相对误差值都比较接近且都是负值。
当然随着偶数的增大,相对误差绝对值将进一步的缩小,这是必然无疑的。
比如5000亿的偶数的素对下界计算值的相对误差绝对值必然进一步缩小:
G(500000000000) = 655630055;
inf( 500000000000 )≈ 631936977.1 , Δ≈-0.0361379 ;infS(m) = 473952732.79 , k(m)= 1.33333
G(500000000002) = 530781937;
inf( 500000000002 )≈ 511599914 , Δ≈-0.0361392 ;infS(m) = 473952732.79 , k(m)= 1.07943
G(500000000004) = 984045373;
inf( 500000000004 )≈ 948474778.2 , Δ≈-0.0361473 ;infS(m) = 473952732.79 , k(m)= 2.0012
G(500000000006) = 567966779;
inf( 500000000006 )≈ 547453424 , Δ≈-0.0361172 ;infS(m) = 473952732.79 , k(m)= 1.15508
G(500000000008) = 491750094;
inf( 500000000008 )≈ 473988706.4 , Δ≈-0.0361187 ;infS(m) = 473952732.79 , k(m)= 1.00008
time start =10:33:05 ,time end =10:48:27 ,time use =
计算式:
inf( 500000000000 ) = 1/(1+ .21 )*( 500000000000 /2 -2)*p(m) ≈ 631936977.1
inf( 500000000002 ) = 1/(1+ .21 )*( 500000000002 /2 -2)*p(m) ≈ 511599914
inf( 500000000004 ) = 1/(1+ .21 )*( 500000000004 /2 -2)*p(m) ≈ 948474778.2
inf( 500000000006 ) = 1/(1+ .21 )*( 500000000006 /2 -2)*p(m) ≈ 547453424
inf( 500000000008 ) = 1/(1+ .21 )*( 500000000008 /2 -2)*p(m) ≈ 473988706.4
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