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 A111181 #14 Jan 15 2025 14:51:39
%S A111181 2,2,3,5,8,10,13,15,19,25,26,32,35,37,41,47,52,54,59,63,65,71,74,80,
%T A111181 88,92,94,98,99,103,116,120,126,128,138,140,145,151,155,161,166,168,
%U A111181 177,179,183,185,196,208,212,214,218,224,225,235,241,247,253,255,260,264
%N A111181 a(n) = prime(n) - pi(n).
%C A111181 Conjecture: There will always be an x such that a(x+1) - a(x) = k for k=1,2.. However, x becomes large when k > 70.
%H A111181 Charles R Greathouse IV, <a href="/A111181/b111181.txt">Table of n, a(n) for n = 1..10000</a>
%F A111181 a(n) = A000040(n) - A000720(n).
%p A111181 a:= n-> ithprime(n)-numtheory[pi](n):
%p A111181 seq(a(n), n=1..60); # _Alois P. Heinz_, Jan 15 2025
%t A111181 Table[Prime[n]-PrimePi[n],{n,60}] (* _Harvey P. Dale_, Mar 11 2012 *)
%o A111181 (PARI) a(n)=prime(n)-primepi(n) \\ _Charles R Greathouse IV_, May 29 2013
%Y A111181 Cf. A000040 (prime), A000720 (pi).
%K A111181 easy,nonn
%O A111181 1,1
%A A111181 _Cino Hilliard_, Oct 22 2005