A049508 - OEIS

A049508

Numbers k such that prime(k) == 3 (mod 10).

2, 6, 9, 14, 16, 21, 23, 27, 30, 38, 40, 44, 48, 51, 56, 61, 62, 65, 71, 74, 76, 84, 86, 90, 96, 99, 103, 108, 112, 117, 119, 122, 124, 130, 132, 137, 143, 147, 150, 153, 162, 166, 170, 174, 179, 183, 185, 188, 191, 192, 196, 198, 200, 208, 213, 220, 224, 227, 231

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OFFSET

1,1

COMMENTS

The asymptotic density of this sequence is 1/4 (by Dirichlet's theorem). - Amiram Eldar, Mar 01 2021

LINKS

Table of n, a(n) for n=1..59.

FORMULA

a(n) = A000720(A030431(n)). - Ray Chandler, Nov 07 2006

MATHEMATICA

Select[Range[240], Mod[Prime[ # ], 10] == 3 &] (* Ray Chandler, Nov 07 2006 *)

CROSSREFS