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A105145
Numbers n such that the string n10001 is prime.
1
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
1,1
LINKS
EXAMPLE
If n=18, then n10001 = 1810001 (prime).
If n=98, then n10001 = 9810001 (prime).
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 *)
CROSSREFS
Sequence in context: A172052 A001101 A088341 * A244603 A120416 A293751
KEYWORD
base,nonn,easy
AUTHOR
Parthasarathy Nambi, Apr 09 2005
STATUS
approved