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 A038812 #20 Apr 03 2023 10:36:09
%S A038812 168,303,430,550,669,783,900,1007,1117,1229,1335,1438,1547,1652,1754,
%T A038812 1862,1960,2064,2158,2262,2360,2464,2564,2668,2762,2860,2961,3055,
%U A038812 3153,3245,3340,3432,3538,3638,3732,3824,3923,4017,4107,4203,4291,4392,4494
%N A038812 Number of primes less than 1000n.
%H A038812 Robert G. Wilson v, <a href="/A038812/b038812.txt">Table of n, a(n) for n = 1..10000</a>
%H A038812 Andrew R. Booker, <a href="https://t5k.org/nthprime/">The Nth Prime Page</a>
%H A038812 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 A038812 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 A038812 Table[ PrimePi[ n*1000 ], {n, 1, 45}]
%o A038812 (PARI) a(n)=primepi(1000*n) \\ _Charles R Greathouse IV_, Apr 29 2015
%Y A038812 Cf. A038801, A028505, A038813, A038814, A038815, A038816, A038817, A038818, A038819, A038820, A038821, A080122, A080123, A080124, A080125, A080126, A080127, A080128, A080129.
%K A038812 nonn
%O A038812 1,1
%A A038812 _Jeff Burch_
%E A038812 Edited and extended by _Robert G. Wilson v_, Jan 29 2003