OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..5000
EXAMPLE
a(5) = 1 because 6*5-1 is prime, a(6) = 0 since 6*6-1 is composite.
MATHEMATICA
Table[If[PrimeQ[6 n - 1], 1, 0], {n, 100}] (* Vincenzo Librandi, Jan 19 2019 *)
PROG
(PARI) a(n) = isprime(6*n-1); \\ Michel Marcus, Jan 19 2019
(Magma) [IsPrime(6*n-1) select 1 else 0: n in[1..100]]; // Vincenzo Librandi, Jan 19 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Washington Bomfim, Oct 27 2009
STATUS
approved