cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A356793 Decimal expansion of sum of squares of reciprocals of lesser twin primes, Sum_{j>=1} 1/(A001359(j))^2.

Original entry on oeis.org

1, 6, 5, 6, 1, 8, 4, 6, 5, 3, 9, 5
Offset: 0

Views

Author

Artur Jasinski, Sep 04 2022

Keywords

Comments

Alternative definition: sum of squares of reciprocals of primes whose distance from the next prime is equal to 2.
Convergence table:
k A001359(k) Sum_{j=1..k} 1/A001359(j)^2
10000000 3285916169 0.165618465394273171950874120818
20000000 7065898967 0.165618465394707600197099741096
30000000 11044807451 0.165618465394836120901019351544
40000000 15151463321 0.165618465394895965582366015390
50000000 19358093939 0.165618465394930089884704869090
60000000 23644223231 0.165618465394951950670948192842
Using the Hardy-Littlewood prediction of the density of twin primes (see A347278), the contribution to the sum after the last entry in the table above can be estimated as 9.056*10^(-14), making the infinite sum ~= 0.16561846539504... . - Hugo Pfoertner, Sep 28 2022

Examples

			0.165618465395...
		

Crossrefs

Extensions

Data extended to ...3, 9, 5 by Hugo Pfoertner, Sep 28 2022

A357059 Decimal expansion of sum of squares of reciprocals of primes whose distance to the next prime is equal to 4, Sum_{j>=1} 1/A029710(j)^2.

Original entry on oeis.org

0, 3, 1, 3, 2, 1, 6, 2, 0, 6, 4, 6
Offset: 0

Views

Author

Artur Jasinski, Sep 10 2022

Keywords

Comments

Convergence table:
k A029710(k) Sum_{j=1..k} 1/A029710(j)^2
10000000 3285441223 0.031321620645456519799598611681
20000000 7067090263 0.031321620645890982910821292996
30000000 11044597393 0.031321620646019474620358985896
40000000 15153534937 0.031321620646079307404248696076
50000000 19360462153 0.031321620646113421819579063642
60000000 23647877233 0.031321620646135276227114122713
70000000 28000392817 0.031321620646150384406674037099

Examples

			0.031321620646...
		

Crossrefs

Programs

  • Mathematica
    aa = {}; Do[g1[2 n] = 0, {n, 1, 1000}]; Do[g2[2 n] = 0, {n, 1, 1000}]; Do[g3[2 n] = 0, {n, 1, 1000}]; Do[g4[2 n] = 0, {n, 1, 1000}]; Do[g[2 n] = 0, {n, 1, 1000}];
    w1 = 3; n = 3; Monitor[While[n < 10^10, w2 = NextPrime[w1]; kk = w2 - w1;
      If[kk < 2000, g[kk] = g[kk] + 1; g1[kk] = g1[kk] + N[1/w1, 1000];g2[kk] = g2[kk] + N[1/w1^2, 1000];g3[kk] = g3[kk] + N[1/w1^3, 1000];g4[kk] = g4[kk] + N[1/w1^4, 1000];
    If[IntegerQ[g[kk]/1000000], Print[{n, w1, kk, g[kk]}];If[kk == 4,AppendTo[aa, {n, w1, kk, g[kk], g1[kk], g2[kk], g3[kk], g4[kk]}]]]];w1 = w2; n++], n];aa
Showing 1-2 of 2 results.