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 A127991 #11 Mar 13 2020 13:08:04
%S A127991 1,1,1,1,1,11,1,3,21,39,1,31,1,1,1,7,297,9,351,1,1,19,91,1,101,141,51,
%T A127991 33,37,49,1,299,37,1,3,39,21,1,11,1,19,1,31,1071,351,9,43,1,481,11,
%U A127991 511,83,3,3,69,1,1,91,1,19,187,39,219,417,553,37,1,1,1,1369,117,693,423,31
%N A127991 2*n^3 - 2*n + 9 divided by 3*largest prime factor.
%H A127991 Amiram Eldar, <a href="/A127991/b127991.txt">Table of n, a(n) for n = 1..10000</a>
%F A127991 a(n) = A127989(n)/(3*A006530(A127989(n))). - _Amiram Eldar_, Mar 13 2020
%t A127991 a = {}; Do[AppendTo[a, 2n^3 - 2n + 9], {n, 1, 300}]; b = {}; Do[c = FactorInteger[a[[n]]]; d = c[[Length[c]]]; AppendTo[b, a[[n]]/(3 d[[1]])], {n, 1, Length[a]}]; b
%o A127991 (PARI) gpf(n)=my(f=factor(n)[,1]); if(n==1,1,f[#f]);
%o A127991 a(n)=my(m=2*n^3-2*n+9); m/gpf(m)/3 \\ _Charles R Greathouse IV_, Mar 13 2020
%Y A127991 Cf. A127979, A127990, A127992.
%K A127991 nonn,easy
%O A127991 1,6
%A A127991 _Artur Jasinski_, Feb 10 2007