A105145 Numbers n such that the string n10001 is prime.
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
Offset: 1
Examples
If n=18, then n10001 = 1810001 (prime). If n=98, then n10001 = 9810001 (prime).
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Maple
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 -
Mathematica
Select[Range[600],PrimeQ[#*10^5+10001]&] (* Harvey P. Dale, Apr 29 2018 *)