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A105145
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Numbers n such that the string n10001 is prime.
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1
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18, 21, 30, 32, 39, 71, 72, 78, 84, 86, 89, 93, 95, 98, 107, 108, 135, 143, 150, 152, 159, 161, 165, 170, 173, 177, 179, 180, 192, 198, 203, 221, 243, 245, 248, 261, 269, 281, 282, 294, 302, 306, 315, 320, 329, 336, 338, 347, 369, 374, 378, 395, 399, 423, 425, 443, 446, 449, 456, 458, 471, 500, 504
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listen;
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internal format)
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OFFSET
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1,1
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LINKS
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EXAMPLE
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If n=18, then n10001 = 1810001 (prime).
If n=98, then n10001 = 9810001 (prime).
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MAPLE
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read("transforms") :
for n from 1 to 1000 do p := digcat2(n, 10001) ; if isprime(p) then printf("%d, ", n); end if; end do: # R. J. Mathar, Feb 02 2011
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MATHEMATICA
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Select[Range[600], PrimeQ[#*10^5+10001]&] (* Harvey P. Dale, Apr 29 2018 *)
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CROSSREFS
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KEYWORD
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base,nonn,easy
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AUTHOR
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STATUS
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approved
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