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A023188 Lonely (or isolated) primes: least prime of distance n from nearest prime (n = 1 or even). 17
2, 5, 23, 53, 409, 293, 211, 1847, 3137, 2179, 3967, 23719, 16033, 40387, 44417, 24281, 158699, 220973, 172933, 321509, 38501, 58831, 203713, 268343, 206699, 829399, 824339, 413353, 2280767, 2305549, 3253631, 1272749, 2401807, 2844833, 3021241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(1)=least prime of distance 1 from nearest prime.

if n>1 a(n)=least prime of distance 2n-2 from nearest prime.

LINKS

Daniel Lignon, Table of n, a(n) for n = 1..65

MATHEMATICA

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; a = Table[0, {35}]; p = 2; q = 3; k = 1; Do[r = NextPrim[q]; m = Min[r - q, q - p]/2; If[m < 35 && a[[m]] == 0, a[[m]] = q]; p = q; q = r, {n, 1, 235000}]

Join[{2}, Transpose[Flatten[Table[Select[Partition[Prime[ Range[ 1000000]], 3, 1], Min[ Differences[#]] == 2n&, 1], {n, 40}], 1]][[2]]](* Harvey P. Dale, Nov 17 2013 *)

CROSSREFS

Related sequences: A023186-A023188, A046929-A046931, A051650, A051652, A051697-A051702, A051728-A051730.

Sequence in context: A308055 A173396 A023186 * A106858 A290887 A219889

Adjacent sequences:  A023185 A023186 A023187 * A023189 A023190 A023191

KEYWORD

nonn

AUTHOR

David W. Wilson

EXTENSIONS

a(36)-a(65) from Daniel Lignon, Aug 07 2015

STATUS

approved

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Last modified May 24 20:53 EDT 2019. Contains 323534 sequences. (Running on oeis4.)