A091123 Number of primes of the form 7k+4 less than 10^n.

0, 3, 26, 202, 1601, 13069, 110776, 960085, 8474021, 75841922, 686340737, 6267984796, 57677570801, 534156825708

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 + 4, {i, 0, 10^7}], PrimeQ[#] &]; Table[Count[p, x_ /; x < 10^n], {n, 7}] (* Robert Price, May 28 2019 *)

Crossrefs

Cf. A091120, A091121, A091122, A091124, A091125.

Sequence in context: A121121 A355047 A228116 * A037790 A037671 A037797

Adjacent sequences: A091120 A091121 A091122 * A091124 A091125 A091126

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