A185712 a(n) = number of primes <= n that end in 3.

0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9

Offset

1,13

Comments

Partial sums of A185706.

Links

G. C. Greubel, Table of n, a(n) for n = 1..5000

A. Granville and G. Martin, Prime number races, arXiv:math/0408319 [math.NT], 2004.

A. Granville and G. Martin, Prime number races, Amer. Math. Monthly, 113 (No. 1, 2006), 1-33.

Mathematica

Accumulate[Table[If[PrimeQ[n] && Mod[n, 10] == 3, 1, 0], {n, 50}]] (* G. C. Greubel, Jul 10 2017 *)

Crossrefs

Cf. A185705, A185706, A185708, A185709, A185711, A185712, A185714, A185715.

Sequence in context: A127321 A111897 A185711 * A328499 A339183 A135665

Adjacent sequences: A185709 A185710 A185711 * A185713 A185714 A185715

Keyword

base,nonn

Author

N. J. A. Sloane, Feb 10 2011

Status

approved