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

Author

Parthasarathy Nambi, Apr 09 2005

Keywords

• base
• nonn
• easy

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

Crossrefs

Cf. A105106, A105107.

Programs

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 *)