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 1-4 of 4 results.

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

A357483 Decimal expansion of sum of squares of reciprocals of primes whose distance to the next prime is equal to 6, Sum_{j>=1} 1/A031924(j)^2.

Original entry on oeis.org

0, 0, 4, 7, 5, 7, 2, 8, 6, 9, 7, 5
Offset: 0

Views

Author

Artur Jasinski, Sep 30 2022

Keywords

Examples

			0.004757286975...
		

Crossrefs

A357528 Decimal expansion of Sum_{j>=1} 1/A031926(j)^2.

Original entry on oeis.org

0, 0, 0, 1, 8, 3, 9, 3, 0, 8, 5, 1, 7
Offset: 0

Views

Author

Artur Jasinski, Oct 02 2022

Keywords

Examples

			0.000183930851...
		

Crossrefs

A380276 Decimal expansion of infinite sum of reciprocals Sum_{n>=1} 1/A357934(n).

Original entry on oeis.org

4, 7, 7, 9, 9, 9, 3
Offset: 0

Views

Author

Artur Jasinski, Jan 18 2025

Keywords

Comments

Sum of reciprocals of product of two distinct lesser twin primes.

Examples

			0.47799932... = 1/15 + 1/33 + 1/51 + 1/55 + 1/85 + 1/87 + ...
		

Crossrefs

Formula

Equals (A342714^2-A356793)/2.
Equals Sum_{m=2} 1/(A001359(m)*A001359(n)).
Showing 1-4 of 4 results.