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A103753
Numbers k such that the string 235711k is prime.
1
9, 27, 39, 43, 73, 79, 109, 117, 129, 187, 213, 219, 241, 243, 247, 253, 297, 319, 327, 331, 361, 367, 369, 387, 417, 433, 447, 457, 471, 493, 513, 523, 537, 547, 577, 591, 601, 621, 633, 639, 643, 661, 699, 703, 709, 717, 727, 757, 759
OFFSET
1,1
LINKS
EXAMPLE
k=9 is in the sequence because 235711k = 2357119 is a prime number.
k=79 is in the sequence because 235711k = 23571179 is a prime number.
k=187 is in the sequence because 235711k = 235711187 is a prime number.
MATHEMATICA
Select[Range[800], PrimeQ[235711*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Jul 20 2024 *)
PROG
(Magma) [ n: n in [1..1750] | IsPrime(Seqint(Intseq(n) cat [1, 1, 7, 5, 3, 2])) ]; // Vincenzo Librandi, Feb 02 2011
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Mar 28 2005
STATUS
approved