A091122 Number of primes of the form 7k+3 less than 10^n.

1, 5, 30, 209, 1613, 13105, 110815, 960213, 8475123, 75843438, 686338138, 6267994788, 57677618350, 534157031248

Offset

1,2

Comments

Computed by T. D. Noe, Dec 19 2003

Links

Table of n, a(n) for n=1..14.

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

Mathematica

p = Select[Table[7 i + 3, {i, 0, 10^7}], PrimeQ[#] &]; Table[Count[p, x_ /; x < 10^n], {n, 7}] (* Robert Price, May 28 2019 *)

Crossrefs

Cf. A091120, A091121, A091123, A091124, A091125.

Sequence in context: A144180 A380621 A222050 * A029587 A365178 A001720

Adjacent sequences: A091119 A091120 A091121 * A091123 A091124 A091125

Keyword

nonn,more

Author

Eric W. Weisstein, Dec 19 2003

Extensions

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

a(11)-a(14) from Hiroaki Yamanouchi, Oct 14 2014

Status

approved