OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
If n=1, then n2101 = 12101 (prime).
If n=31, then n2101 = 312101 (prime).
If n=63, then n2101 = 632101 (prime).
MATHEMATICA
Select[Range[400], PrimeQ[10000#+2101]&] (* Harvey P. Dale, Jul 20 2015 *)
PROG
(Magma) [ n: n in [1..700] | IsPrime(Seqint([1, 0, 1, 2] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 03 2011
(PARI) is(n)=isprime(10000*n+2101) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
base,nonn,easy
AUTHOR
Parthasarathy Nambi, Mar 20 2005
STATUS
approved