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 A196671 #16 Aug 13 2013 02:56:41 %S A196671 0,0,42,516,4498,414123 %N A196671 The number of Chebyshev primes (of index 1) less than 10^n, (n=1,2,...). %C A196671 The Chebyshev primes (of index 1) are such odd primes that satisfy li[psi(p)]-li[psi(p-1)]<1 (sequence A196667), where li(x) is the logarithmic integral and psi(x) is the Chebyshev's psi function. %C A196671 The present sequence lists the number of Chebyshev primes less than 10^n, (n=1,2,...). %C A196671 The sequence suggests the density pi(x)/2 for the Chebyshev primes, where pi(x) is the density of primes. %H A196671 M. Planat and P. Solé, <a href="http://arxiv.org/abs/1109.6489">Efficient prime counting and the Chebyshev primes</a> arXiv:1109.6489 [math.NT] %Y A196671 Cf. A196667. %K A196671 nonn %O A196671 1,3 %A A196671 _Michel Planat_, Oct 05 2011