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A117626 Least prime which stays prime when end digits (on both sides) are repeated n times. 0
2, 131, 113, 137, 197, 113, 139, 139, 223, 199, 137, 229, 127, 137, 271, 461, 167, 113, 131, 137, 421, 149, 167, 389, 337, 191, 419, 239, 263, 113, 373, 593, 211, 223, 683, 251, 137, 277, 359, 127, 281, 347, 193, 277, 151, 197, 199, 1321, 337, 1399, 547, 157 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..51.

EXAMPLE

We thus have successively the derived primes: 11311, 1111333, 111137777, 11111977777, 1111111333333, 111111139999999, ... .

MATHEMATICA

f[n_] := Block[{k = 1}, While[id = IntegerDigits@ Prime@ k; !PrimeQ[ FromDigits@ Join[ Table[id[[1]], {n}], id, Table[id[[ -1]], {n}]]], k++ ]; Prime@k]; Table[ f@n, {n, 0, 51}] (* Robert G. Wilson v *)

CROSSREFS

Sequence in context: A218434 A303445 A158110 * A142251 A125633 A089662

Adjacent sequences:  A117623 A117624 A117625 * A117627 A117628 A117629

KEYWORD

base,nonn

AUTHOR

Lekraj Beedassy, Apr 08 2006

EXTENSIONS

More terms from Robert G. Wilson v, Apr 12 2006

STATUS

approved

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Last modified October 22 22:34 EDT 2019. Contains 328335 sequences. (Running on oeis4.)