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A112394 Smallest prime obtained by appending 3's to n, as n runs through the numbers not divisible by 3. 2
13, 23, 43, 53, 73, 83, 103, 113, 1333333333333333, 1433, 163, 173, 193, 20333, 223, 233, 2533333333, 263, 283, 293, 313, 323333, 3433, 353, 373, 383 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term is (probably) 40 followed by 483 3's, followed by 4133, 433, 443, 463, 4733, 4933, 503, 523, 5333, 55333, 563, 58333333, 593, 613, 6233333, 643, 653, 673, 683, 7033333, 71333, 733, 743, 76333, 773, 7933, 803333, 823, 83333333, 853, 863, 883, 8933, 9133, 92333, 9433, 953, 9733, 983, ... - Lambert Herrgesell (zero815(AT)googlemail.com), Dec 09 2005

LINKS

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

EXAMPLE

1333333333333333 is a prime but 133,1333,13333 etc. are not primes.

MATHEMATICA

sp3[n_]:=Module[{idn=IntegerDigits[n], k=1}, While[!PrimeQ[FromDigits[ Join[ idn, PadRight[ {}, k, 3]]]], k++]; FromDigits[Join[idn, PadRight[{}, k, 3]]]]; sp3/@Drop[Range[40], {3, -1, 3}] (* Harvey P. Dale, Jul 11 2017 *)

CROSSREFS

Cf. A112386.

Sequence in context: A119488 A165350 A236418 * A067227 A240113 A256177

Adjacent sequences:  A112391 A112392 A112393 * A112395 A112396 A112397

KEYWORD

nonn,base

AUTHOR

Parthasarathy Nambi, Dec 05 2005

EXTENSIONS

More terms from Lambert Herrgesell (zero815(AT)googlemail.com), Dec 09 2005

STATUS

approved

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Last modified November 18 02:03 EST 2019. Contains 329242 sequences. (Running on oeis4.)