A167021 a(n) = 1 iff 6n+1 is prime.

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

Offset

1,1

Links

Table of n, a(n) for n=1..105.

Index entries for characteristic functions

Example

a(3) = 1 because 6*3+1 is prime;
a(4) = 0 since 6*4+1 is composite.

Mathematica

If[PrimeQ[6#+1], 1, 0]&/@Range[120] (* Harvey P. Dale, Apr 03 2012 *)

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..105]]; // Marius A. Burtea, Oct 06 2019

Crossrefs

Cf. A024899, A167020, A132350. For n < 14, a(n) = A132350(n).

Sequence in context: A219009 A353519 A267708 * A267687 A304653 A132350

Adjacent sequences: A167018 A167019 A167020 * A167022 A167023 A167024

Keyword

nonn

Author

Washington Bomfim, Oct 27 2009

Status

approved