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A126088 Least k such that k*(p(n+1)#-p(n)#)-1 and k*(p(n+1)#-p(n)#)+1 are twin primes. 1
1, 3, 1, 3, 2, 4, 13, 5, 9, 10, 6, 8, 61, 121, 3, 13, 17, 79, 45, 27, 120, 145, 113, 11, 41, 198, 102, 139, 202, 103, 23, 48, 177, 43, 486, 169, 501, 251, 106, 132, 40, 155, 1890, 116, 584, 107, 629, 241, 1331, 2078, 562, 57, 52, 71, 567, 73, 262, 332, 483, 419, 423 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..200

EXAMPLE

3*(2*3*5-2*3)-1=71 3*(2*3*5-2*3)+1=73; 71 and 73 twin primes so k(2)=3

MATHEMATICA

ktp[n_]:=Module[{k=1}, While[!PrimeQ[k*n-1]||!PrimeQ[k*n+1], k++]; k]; With[ {prmrls=#[[2]]-#[[1]]&/@Partition[FoldList[Times, Prime[Range[ 70]]], 2, 1]}, ktp/@prmrls] (* Harvey P. Dale, Mar 31 2017 *)

CROSSREFS

Sequence in context: A279633 A126208 A287863 * A294248 A085671 A126324

Adjacent sequences:  A126085 A126086 A126087 * A126089 A126090 A126091

KEYWORD

nonn

AUTHOR

Pierre CAMI, Mar 03 2007

STATUS

approved

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Last modified February 22 17:35 EST 2019. Contains 320400 sequences. (Running on oeis4.)