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 A348836 #13 Nov 11 2021 11:37:55 %S A348836 1,2,5,9,17,23,34,41,56,81,92,124,146,157,185,222,270,283,334,368,386, %T A348836 444,481,548,635,681,703,753,780,832,1013,1068,1160,1192,1345,1376, %U A348836 1472,1577,1648,1752,1864,1899,2090,2129,2197,2240,2492,2749,2837,2881,2976,3107,3159,3389,3540 %N A348836 a(n) is the number of primes <= prime(n)^2/2. %H A348836 Michel Marcus, <a href="/A348836/b348836.txt">Table of n, a(n) for n = 1..2000</a> %F A348836 a(n) = A000720(prime(n)^2/2). %t A348836 a[n_] := PrimePi[Prime[n]^2/2]; Array[a, 55] (* _Amiram Eldar_, Nov 01 2021 *) %o A348836 (PARI) a(n) = primepi(prime(n)^2/2); %Y A348836 First column of A283235. %Y A348836 Cf. A000040, A000720, A000879, A001248. %K A348836 nonn %O A348836 1,2 %A A348836 _Michel Marcus_, Nov 01 2021