A185709 Characteristic function of positive numbers that are primes ending in 9.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65539

Index entries for characteristic functions

Mathematica

Table[If[PrimeQ[n]&&Mod[n, 10]==9, 1, 0], {n, 120}] (* Harvey P. Dale, Oct 22 2017 *)

Prog

(Scheme) (define (A185709 n) (if (= 9 (modulo n 10)) (A010051 n) 0)) ;; Antti Karttunen, Dec 06 2017

Crossrefs

Characteristic function of A030433.

Cf. A010051.

Sequence in context: A304571 A181838 A181837 * A011732 A353473 A011731

Adjacent sequences: A185706 A185707 A185708 * A185710 A185711 A185712

Keyword

base,nonn

Author

N. J. A. Sloane, Feb 10 2011

Status

approved