

A110055


Numbers n such that the string 333n is the decimal expansion of a prime number.


0



1, 11, 17, 29, 31, 43, 47, 49, 53, 59, 77, 91, 101, 103, 107, 131, 139, 161, 187, 197, 209, 227, 233, 253, 269, 271, 283, 287, 299, 323, 331, 337, 341, 349, 367, 383, 397, 419, 427, 433, 439, 449, 451, 457, 479, 491, 493, 497, 503, 517, 533, 539, 563, 581
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..54.


EXAMPLE

1 is in the sequence because 3331 is prime.
59 is in the sequence because 33359 is prime.
107 is in the sequence because 333107 is prime.


MATHEMATICA

Select[Range[1000], PrimeQ[FromDigits[Join[{3, 3, 3}, IntegerDigits[ # ]]]] &] (Delarte)


PROG

(MAGMA) [ n: n in [1..600]  IsPrime(Seqint(Intseq(n) cat [3, 3, 3])) ]; // Klaus Brockhaus, Feb 03 2011


CROSSREFS

Sequence in context: A079367 A120139 A191061 * A240095 A105886 A225493
Adjacent sequences: A110052 A110053 A110054 * A110056 A110057 A110058


KEYWORD

nonn,base


AUTHOR

Parthasarathy Nambi, Sep 04 2005


EXTENSIONS

More terms from Alonso del Arte, Sep 06 2005


STATUS

approved



