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 A127990 #11 Mar 13 2020 12:43:01
%S A127990 3,7,19,43,83,13,227,113,23,17,883,37,1459,1823,2243,389,11,431,13,
%T A127990 5323,6163,373,89,9203,103,83,257,443,439,367,19843,73,647,26183,9521,
%U A127990 797,1607,36559,3593,42643,2417,49367,1709,53,173,7207,1609,73699,163,7573
%N A127990 Largest prime factor of 2*n^3 - 2*n + 9.
%C A127990 All numbers generated by the irreducible polynomial 2*n^3 - 2*n + 9 (A127989) are odd and composite. Smallest prime factor A127991, number of prime factors A127992
%H A127990 Amiram Eldar, <a href="/A127990/b127990.txt">Table of n, a(n) for n = 1..10000</a>
%F A127990 a(n) = A006530(A127989(n)). - _Amiram Eldar_, Mar 13 2020
%t A127990 a = {}; Do[AppendTo[a, 2n^3 - 2n + 9], {n, 1, 300}]; b = {}; Do[c = FactorInteger[a[[n]]]; d = c[[Length[c]]]; AppendTo[b, d[[1]]], {n, 1, Length[a]}]; b
%Y A127990 Cf. A006530, A127989, A127991, A127992.
%K A127990 nonn
%O A127990 1,1
%A A127990 _Artur Jasinski_, Feb 10 2007