This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A227799 #13 Jun 27 2017 15:42:34 %S A227799 4999999999,1666666666,666666666,380952380,207792207,159840159, %T A227799 112828348,95013343,74358271,56409724,50950713,41311372,36273411, %U A227799 33742734,30153115,26170720,23065826,21931483,19640105,18256894,17506397,15954848,14993294,13813524,12531256 %N A227799 Number of composites removed in each step of the Sieve of Eratosthenes for 10^10. %C A227799 a(n) = the number of composites <= 10^10 for which the n-th prime is the least prime factor. %C A227799 pi(sqrt(10^10)) = the number of terms of this sequence. %C A227799 The sum of a(n) for n = 1..3401 = A000720(10^10) + A065855(10^10). %H A227799 Eric F. O'Brien, <a href="/A227799/b227799.txt">Table of n, a(n) for n = 1..9592</a> %e A227799 a(1) = 10^10 \ 2 - 1. %e A227799 a(2) = 10^10 \ 3 - 10^10 \ (2*3) - 1. %e A227799 a(3) = 10^10 \ 5 - 10^10 \ (2*5) - 10^10 \ (3*5) + 10^10 \ (2*3*5) - 1. %e A227799 a(4) = 10^10 \ 7 - 10^10 \ (2*7) - 10^10 \ (3*7) - 10^10 \ (5*7) + 10^10 \ (2*3*7) + 10^10 \ (2*5*7) + 10^10 \ (3*5*7) - 10^10 \ (2*3*5*7) - 1. %Y A227799 Cf. A133228, A145538, A145539, A145540, A145583, A227155, A227797, A227798, A145532, A145533, A145534, A145535, A145536, A145537. %K A227799 nonn,fini %O A227799 1,1 %A A227799 _Eric F. O'Brien_, Jul 31 2013