cp's OEIS Frontend

A028505 Number of primes <= 100*n.

%I A028505 #27 Feb 12 2025 03:17:37
%S A028505 25,46,62,78,95,109,125,139,154,168,184,196,211,222,239,251,266,278,
%T A028505 290,303,317,327,342,357,367,378,393,407,419,430,442,452,463,478,489,
%U A028505 503,516,528,539,550,565,574,590,599,610,622,634,646,654,669,681,692,702
%N A028505 Number of primes <= 100*n.
%D A028505 Fred W. Helenius (fredh(AT)ix.netcom.com), posting to newsgroup rec.puzzles, Dec. 1997.
%H A028505 Robert G. Wilson v, <a href="/A028505/b028505.txt">Table of n, a(n) for n = 1..10000</a>
%H A028505 J. Betrema, <a href="http://www.labri.fr/Perso/~betrema/deug/poly/annexes/premiers.html">Table et repartition des nombres premiers inferieurs a 10000</a>
%H A028505 A. Booker, <a href="https://t5k.org/nthprime">The Nth Prime Page</a>
%H A028505 Thomas Ehrenborg, <a href="https://arxiv.org/abs/2502.06804">Gauss Circle Primes</a>, arXiv:2502.06804 [math.GM], 2025. See Table 2 p. 4.
%H A028505 Thomas R. Nicely, <a href="https://faculty.lynchburg.edu/~nicely/index.html">Some Results of Computational Research in Prime Numbers</a> [See local copy in A007053]
%H A028505 Tomás Oliveira e Silva, <a href="http://sweet.ua.pt/tos/primes.html">Tables of values of pi(x) and of pi2(x)</a>
%t A028505 Table[ PrimePi[ n*100 ], {n, 55}] (* _Robert G. Wilson v_, Jan 29 2003 *)
%o A028505 (Macsyma) for n:1 through 50 do print(prime_pi(100*n));
%o A028505 (PARI) a(n)=primepi(100*n) \\ _Charles R Greathouse IV_, Apr 28 2015
%Y A028505 Cf. A000720, A038801, A038812, A038813, A038814, A038815, A038816, A038817, A038818, A038819, A038820, A038821, A080122, A080123, A080124, A080125, A080126, A080127, A080128, A080129.
%K A028505 nonn
%O A028505 1,1
%A A028505 Chris Cole (chris(AT)questrel.com)