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.

A095390 Least inverse of A095389.

Original entry on oeis.org

64, 28, 11, 14, 5, 3, 2, 1, 968
Offset: 0

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Author

Labos Elemer, Jun 16 2004

Keywords

Comments

It is believed (or proved) that values at n > 8 indices do not occur, except once, at the beginning when 13 lesser twins in 210.0+R range, where R is the reduced residues modulo 210.

Examples

			a(13) = 0 because A095389(0) = 13.
a(1) = 28 means that in reduced residue system 210.28+R exactly 1 lesser-twin-prime arises; see A095389.
a(8) = 968 means that at surprisingly high density of twin primes [8 cases] occur in range of {210.968+r, 210.968+r+2}, as follows: {203309, 203321, 203339, 203351, 203381, 203417, 203429, 203459}.
		

Crossrefs

Programs

  • Mathematica
    {k=0, ta=Table[0, {100000}]}; Do[{m=0};Do[s=210k+r; s1=210k+r+2; If[PrimeQ[s]&&PrimeQ[s+2], m=m+1], {r, 1, 210}];ta[[k]]=m, {k, 1, 100000}]; Table[Min[Flatten[Position[ta, j]]], {j, 0, 15}]

Formula

a(n) = min{x: A095389(x) = n}

Extensions

Edited by Charles R Greathouse IV, Oct 27 2010