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.

A093738 Number of pairs of consecutive prime (p,q) with q-p=6 and q < 10^n.

Original entry on oeis.org

0, 7, 44, 299, 1940, 13549, 99987, 768752, 6089791, 49392723, 408550278, 3435528229, 29289695650, 252672394234, 2201981901415, 19360330918473, 171550299264139, 1530609037414453
Offset: 1

Views

Author

Enoch Haga, Apr 15 2004

Keywords

Comments

Note that one has to be careful to distinguish between pairs of consecutive primes (p,q) with q-p = 6 (A031924), and pairs of primes (p,q) with q-p = 6 (A023201). Here we consider the former, whereas A080841 considers the latter. - N. J. A. Sloane, Mar 07 2021

Examples

			a(2) = 7 because there are 7 prime gaps of 6 below 10^2.
		

Crossrefs

Programs

  • Mathematica
    Accumulate@ Array[Count[Differences@ Prime@ Range[PrimePi[10^(# - 1) + 1], PrimePi[10^# - 1]], 6] &, 8] (* Michael De Vlieger, Apr 09 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

A093740 Number of prime pairs below 10^n having a difference of 10.

Original entry on oeis.org

0, 0, 16, 119, 916, 7079, 54431, 430016, 3484767, 28764495, 241298621, 2052293026, 17663498098, 153590992984, 1347587381486, 11917605558274, 106139298948562, 951243890034661
Offset: 1

Views

Author

Enoch Haga, Apr 15 2004

Keywords

Examples

			a(3) = 16 because there are 16 prime gaps of 10 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 20 2012
a(14)-a(18) from S. Herzog's website added by Giovanni Resta, Aug 14 2018
Showing 1-2 of 2 results.