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.

A093742 Number of prime pairs below 10^n having a difference of 14.

Original entry on oeis.org

0, 0, 7, 54, 484, 4233, 35394, 293201, 2464565, 20943953, 179718000, 1556469349, 13597962107, 119731244640, 1061769557793, 9476573902533, 85076550195696, 767846949916102
Offset: 1

Views

Author

Enoch Haga, Apr 15 2004

Keywords

Examples

			a(3) = 7 because there are 7 prime gaps of 14 below 10^3.
		

Crossrefs

Programs

  • UBASIC
    20 N=1:dim T(34); 30 A=nxtprm(N); 40 N=A; 50 B=nxtprm(N); 60 D=B-A; 70 for x=2 to 34 step 2; 80 if D=X and B<10^2+1 then T(X)=T(X)+1; 90 next X; 100 if B>10^2+1 then 140; 110 B=A; 120 N=N+1; 130 goto 30; 140 for x=2 to 34 step 2; 150 print T(X);, 160 next (This program simultaneously finds values from 2 to 34 -- if gap=2 add 1-- adjust lines 80 and 100 for desired 10^n)

Extensions

a(10)-a(13) from Washington Bomfim, Jun 22 2012
a(14)-a(18) from S. Herzog's website added by Giovanni Resta, Aug 14 2018

A093744 Number of prime pairs below 10^n having a difference of 18.

Original entry on oeis.org

0, 0, 1, 40, 514, 4909, 43851, 384738, 3351032, 29189691, 255371697, 2246576317, 19878698732, 176913444597, 1583135619012, 14240370591853, 128711774414592, 1168583066366245
Offset: 1

Views

Author

Enoch Haga, Apr 15 2004

Keywords

Examples

			a(4) = 40 because there are 40 prime gaps of 18 below 10^4.
		

Crossrefs

Programs

  • Mathematica
    Table[Count[Differences[Prime[Range[PrimePi[10^n]]]],18],{n,8}] (* The program generates the first 8 terms in the sequence. To generate more increase the n constant but the program may take a long time to run. *) (* Harvey P. Dale, Sep 03 2021 *)
  • UBASIC
    20 N=1:dim T(34); 30 A=nxtprm(N); 40 N=A; 50 B=nxtprm(N); 60 D=B-A; 70 for x=2 to 34 step 2; 80 if D=X and B<10^2+1 then T(X)=T(X)+1; 90 next X; 100 if B>10^2+1 then 140; 110 B=A; 120 N=N+1; 130 goto 30; 140 for x=2 to 34 step 2; 150 print T(X);, 160 next (This program simultaneously finds values from 2 to 34 - if gap=2 add 1- adjust lines 80 and 100 for desired 10^n)

Extensions

a(10)-a(13) from Washington Bomfim, Jun 22 2012
a(14)-a(18) from S. Herzog's website added by Giovanni Resta, Aug 14 2018
Showing 1-2 of 2 results.