A167020 a(n) = 1 iff 6n-1 is prime.

1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Index entries for characteristic functions

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

Cf. A024898, A167021.

Sequence in context: A237048 A344880 A379406 * A236862 A163812 A163818

Adjacent sequences: A167017 A167018 A167019 * A167021 A167022 A167023

Keyword

nonn

Author

Washington Bomfim, Oct 27 2009

Status

approved