A160916 Averages of twin prime pairs which are a sum of averages of two consecutive twin prime pairs.
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
Keywords
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.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Crossrefs
Cf. A014574.
Programs
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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
Comments