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 A145203 #19 Dec 29 2023 06:12:49 %S A145203 4,8,12,18,31,58,67,78,101,115,157,260,279,297,337,361,406,449,500, %T A145203 578,604,688,716,808,907,937,1037,1146,1259,1407,1447,1577,1614,1926, %U A145203 2204,2253,2511,2613,2725,2772,2882,2992,3576,3762,4480 %N A145203 a(n) = pi(A002407(n)). %H A145203 Chai Wah Wu, <a href="/A145203/b145203.txt">Table of n, a(n) for n = 1..10000</a> %e A145203 From _Rémi Guillaume_, Dec 28 2023: (Start) %e A145203 a(5) = pi(A002407(5)) = pi(127) = 31, i.e., A002407(5) = prime(31). %e A145203 a(6) = pi(A002407(6)) = pi(271) = 58, i.e., A002407(6) = prime(58). (End) %o A145203 (PARI) j=[];for(n=1,300,if(isprime(n^3-(n-1)^3),j=concat(j,primepi(n^3-(n-1)^3))));j %o A145203 (Python) %o A145203 from sympy import isprime, primepi %o A145203 A145203_list = [primepi(3*n*(n+1)+1) for n in range(10**3) if isprime(3*n*(n+1)+1)] # _Chai Wah Wu_, Jun 02 2017 %Y A145203 Cf. A002407, A000720 (pi), A000040 (prime). %K A145203 nonn %O A145203 1,1 %A A145203 _Alexander R. Povolotsky_, Oct 04 2008