login
Primes of the form 100n - 1.
3

%I #8 Sep 08 2022 08:45:14

%S 199,499,599,1399,1499,1699,1999,2099,2399,2699,2999,3299,3499,4099,

%T 4799,4999,5099,5399,6199,6299,6599,6899,7499,7699,8599,8699,8999,

%U 9199,10099,10399,10499,10799,11299,11399,11699,12799,12899,13099,13399

%N Primes of the form 100n - 1.

%C If n is of the form 3x + 1 then 100n - 1 will be of the form 100*3x + 99, that is, a multiple of 3. The factorizations of other nonprime 100n - 1 has a much more complicated pattern.

%H Vincenzo Librandi, <a href="/A095995/b095995.txt">Table of n, a(n) for n = 1..1000</a>

%e a(2)=499 because 499 = 100 * 5 - 1.

%t Select[ 100Range[134] - 1, PrimeQ[ # ] &]

%t Select[Table[100n-1,{n,0,800}],PrimeQ] (* _Vincenzo Librandi_, Jul 17 2012 *)

%o (Magma) [a: n in [0..135] | IsPrime(a) where a is 100*n-1]; // _Vincenzo Librandi_, Jul 17 2012

%Y Cf. A062800.

%K nonn,easy

%O 1,1

%A _Alonso del Arte_, Jul 19 2004

%E Edited by _Robert G. Wilson v_, Jul 23 2004