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 A342566 #6 May 05 2021 08:42:21 %S A342566 2,3,5,7,11,13,29,43,83,239,463,911,1483,1721,3067,4187,10613,12433, %T A342566 15287,26447 %N A342566 Noncube factors k > 0 such that k*x^3 + 1 produces a new minimum of its Hardy-Littlewood constant. %C A342566 a(21)>40000. %C A342566 For more information and references see A331950. %C A342566 4187=53*79 is the first nonprime term. %e A342566 n a(n) Hardy-Littlewood np / (expected number of primes) %e A342566 constant (rounded) obtained from Li(a(n)*(10^9)^3+1) %e A342566 np (x<=10^9) (similar to table in A331946) %e A342566 1 2 2.597079115 43503785 2.69054 %e A342566 2 3 2.085815908 34707483 2.16060 %e A342566 3 5 1.428347905 23566489 1.47910 %e A342566 4 7 1.290763004 21179402 1.33641 %e A342566 5 11 1.241279598 20211462 1.28447 %e A342566 ... %e A342566 18 12433 0.450506688 6582602 0.46462 %e A342566 19 15287 0.422449638 6150009 0.43536 %e A342566 20 26447 0.418323708 6045844 0.43130 %Y A342566 Cf. A331946 (similar for k*x^2+1), A331950, A342549. %K A342566 nonn,hard,more %O A342566 1,1 %A A342566 _Hugo Pfoertner_, May 03 2021