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 A276824 #43 Nov 11 2016 21:16:52
%S A276824 0,-1,-1,-2,2,-2,3,-5,-1,17,2,22,25,2,1,28,47,18,41,36,-7,20,12,37,
%T A276824 103,91,30,10,-57,-70,157,125,153,63,213,120,145,168,129,154,170,65,
%U A276824 230,114,61,-63,189,445,386,239,172,203,52,239,257,268
%N A276824 a(n) = p-s, where s = Sum_{i=1..n} prime(i) and p = primepi(prime(n)^2).
%F A276824 a(n) = A000879(n) - A007504(n).
%e A276824 n= 10, prime(10) = 29, s = Sum_{i=1,10} prime(i) = 2+3+5+7+11+13+17+19+23+29 = 129,
%e A276824 p= primepi(29^2) = primepi(841) = 146. So a(10) = p-s = 146 - 129 = 17.
%o A276824 (PARI) a(n) = primepi(prime(n)^2) - sum(k=1, n, prime(k)); \\ _Michel Marcus_, Oct 17 2016
%Y A276824 Cf. A000879, A007504.
%K A276824 sign
%O A276824 1,4
%A A276824 _Dimitris Valianatos_, Sep 27 2016