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 A099802 #24 Dec 07 2019 12:18:24 %S A099802 1,2,3,4,4,5,6,6,7,8,8,9,9,9,10,11,11,11,12,12,13,14,14,15,15,15,16, %T A099802 16,16,17,18,18,18,19,19,20,21,21,21,22,22,23,23,23,24,24,24,24,25,25, %U A099802 26,27,27,28,29,29,30,30,30,30,30,30,30,31,31,32,32,32,33,34,34,34,34,34 %N A099802 Bisection of A000720. %C A099802 Maximal number of primes possible in a string of 2n consecutive numbers. - _Lekraj Beedassy_, Dec 04 2004 %C A099802 a(n) = A139325(n,1) + 1. - _Reinhard Zumkeller_, Apr 14 2008 %C A099802 Or the number of primes <= 2n. - _Juri-Stepan Gerasimov_, Oct 29 2009 %F A099802 a(n) = A000720(n) + A035250(n) - A010051(n). - _Reinhard Zumkeller_, Jul 05 2010 %F A099802 a(n) = A000720(2*n). - _Wesley Ivan Hurt_, Jun 16 2013 %p A099802 with(numtheory):seq(pi(2*n),n=1..86); # _Emeric Deutsch_, Apr 12 2005 %o A099802 (Sage) [prime_pi(2*n) for n in range(1, 75)] # _Zerinvary Lajos_, Jun 06 2009 %o A099802 (PARI) a(n)=primepi(2*n) \\ _Charles R Greathouse IV_, Sep 02 2015 %Y A099802 Cf. A099081. %K A099802 nonn,easy %O A099802 1,2 %A A099802 _N. J. A. Sloane_, Nov 19 2004 %E A099802 More terms from _Emeric Deutsch_, Apr 12 2005