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 A122933 #7 Mar 16 2015 22:31:06
%S A122933 2,3,5,8,9,12,14,18,23,28,42,58,61,70,91,95,101,103,132,142,150,161,
%T A122933 167,170,248,347,361,382,409,412,424,463,476,514,532,561,645,666,710,
%U A122933 724,736,788,795,869,999,1010,1083,1106,1124,1136,1143,1149,1163,1205,1244
%N A122933 a(n)-th prime is equal to the sum_{i=1..k} pi(i) for some k (cf. A000720).
%C A122933 A046992 is sum_{k=1..n} pi(k). A122516 are the members of A046992 which are primes.
%C A122933 Primes in A046992[n] are {3,5,11,19,23,37,43,61,...} = A122516[n] = Prime[a(n)].
%F A122933 a(n) = PrimePi[ A122516[n] ].
%e A122933 A122516[n] begins {3,5,11,19,23,37,43,61,83,107,181,271,...}.
%e A122933 So a(1) = 2 because A122516[1] 3 = Prime[2].
%e A122933 a(2) = 3 because A122516[2] = 5 = Prime[3].
%e A122933 a(3) = 5 because A122516[3] = 11 = Prime[5].
%t A122933 PrimePi[Flatten[Table[If[PrimeQ[Sum[ PrimePi[n], {n, 1, m}]], Sum[PrimePi[n], {n, 1, m}], {}], {m, 1, 500}]]]
%Y A122933 Cf. A122516, A046992, A000720, A020641.
%K A122933 nonn
%O A122933 1,1
%A A122933 _Alexander Adamchuk_, Sep 20 2006
%E A122933 Edited by _Robert G. Wilson v_, Sep 28 2006