A091115 Number of primes of the form 6k+1 less than 10^n.

1, 11, 80, 611, 4784, 39231, 332194, 2880517, 25422713, 227523123, 2059018668, 18803933520, 173032692013, 1602470745574, 14922284472148, 139619169015686

Offset

1,2

Comments

Computed by T. D. Noe, Dec 19 2003.

Links

Table of n, a(n) for n=1..16.

Eric Weisstein's World of Mathematics, Modular Prime Counting Function

Mathematica

p = Select[Table[6 i + 1, {i, 0, 10^7}], PrimeQ[#] &]; Table[Count[p, x_ /; x < 10^n], {n, 7}] (* Robert Price, May 29 2019 *)

Crossrefs

Cf. A002476, A091116.

Sequence in context: A127021 A326243 A091098 * A024146 A233176 A156847

Adjacent sequences: A091112 A091113 A091114 * A091116 A091117 A091118

Keyword

nonn,more

Author

Eric W. Weisstein, Dec 19 2003

Extensions

a(10) from Robert G. Wilson v, Dec 22 2003

a(11)-a(13) from Chai Wah Wu, Jul 01 2019

a(14)-a(15) from Griffin N. Macris, Sep 13 2020

a(16) from Griffin N. Macris, Jan 18 2023

Status

approved