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A165292
Primes obtained from other primes by pre-concatenating with 3.
6
37, 311, 313, 317, 331, 337, 347, 353, 359, 367, 373, 379, 383, 389, 397, 3109, 3137, 3163, 3167, 3181, 3191, 3229, 3251, 3257, 3271, 3307, 3313, 3331, 3347, 3359, 3373, 3389, 3433, 3449, 3457, 3461, 3463, 3467, 3491, 3499, 3541, 3547, 3557, 3571, 3593
OFFSET
1,1
COMMENTS
The primes are considered in increasing order. These primes are obtained by adding 30, 300, 3000, ... to other primes.
EXAMPLE
The prime 3389 is obtained from the prime 389 by pre-concatenating with 3.
MATHEMATICA
Select[(FromDigits[Join[{3}, IntegerDigits[#]]]&/@Prime[Range[200]]), PrimeQ] (* Harvey P. Dale, Mar 04 2011 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Sep 13 2009
EXTENSIONS
359 inserted by R. J. Mathar, Sep 21 2009
STATUS
approved