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.

A160916 Averages of twin prime pairs which are a sum of averages of two consecutive twin prime pairs.

Original entry on oeis.org

18, 30, 72, 102, 660, 1092, 1302, 2082, 2112, 2382, 2592, 2970, 4242, 4272, 4650, 4722, 4932, 5442, 5520, 6690, 6762, 7590, 8220, 9000, 10332, 10860, 11160, 11718, 11970, 13002, 16452, 17658, 18522, 20232, 22278, 23040, 23910, 24180, 24918
Offset: 1

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Comments

Values A014574(j) of the form A014574(k) + A014574(k+1).

Examples

			18=A014574(4) is in the sequence because it equals A014574(2)+A014574(3) = 6+12.
30=A014574(5) is in the sequence because it equals A014574(3)+A014574(4) = 12+18.
72=A014574(8) is in the sequence because it equals A014574(5)+A014574(6) = 30+42.
		

Crossrefs

Cf. A014574.

Programs

  • Mathematica
    PrimeNextTwinAverage[n_]:=Module[{k},k=n+1;While[ !PrimeQ[k-1]||!PrimeQ[k+1], k++ ];k];lst={};Do[If[PrimeQ[n-1]&&PrimeQ[n+1],a=n;a+=PrimeNextTwinAverage[a]; If[PrimeQ[a-1]&&PrimeQ[a+1],AppendTo[lst,a]]],{n,8!}];lst
    Select[Total/@Partition[Mean/@Select[Partition[Prime[Range[ 2000]],2,1], #[[2]] - #[[1]] ==2&],2,1],AllTrue[#+{1,-1},PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 12 2020 *)

Extensions

Comment and examples edited by R. J. Mathar, Jul 31 2007