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 A338361 #16 Jan 30 2024 11:42:21 %S A338361 2,4,6,8,12,15,19,22,26,32,35,41,45,48,52,59,65,68,74,79,82,88,92,98, %T A338361 106,111,114,118,121,126,139,144,150,153,162,165,172,178,182,189,195, %U A338361 198,209,212,216,219,230,241,245,248,253,260,263,274,280,286,293,296,302,306,309,320,333 %N A338361 Indices of primes in A283312. %H A338361 N. J. A. Sloane, <a href="/A338361/b338361.txt">Table of n, a(n) for n = 1..7099</a> %F A338361 a(n) = p(n) + n - 1 - pi(p(n)/2), where p(n) = prime(n) and pi(i) = A000720(i). %p A338361 with(NumberTheory); %p A338361 A338361 := n -> ithprime(n)+n-1-pi(ithprime(n)/2); %t A338361 A338361[n_] := Prime[n] - PrimePi[Prime[n]/2] + n - 1; %t A338361 Array[A338361, 100] (* _Paolo Xausa_, Jan 30 2024 *) %Y A338361 Cf. A000720, A283312. %K A338361 nonn %O A338361 1,1 %A A338361 _N. J. A. Sloane_, Nov 03 2020