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 A191012 #22 Sep 08 2022 08:45:57 %S A191012 0,1,22,183,820,2605,6666,14707,29128,53145,90910,147631,229692, %T A191012 344773,501970,711915,986896,1340977,1790118,2352295,3047620,3898461, %U A191012 4929562,6168163,7644120,9390025,11441326,13836447,16616908,19827445 %N A191012 a(n) = n^5 - n^4 + n^3 - n^2 + n. %C A191012 n such that x^5 + x^4 + x^3 + x^2 + x + n factors over the integers. %H A191012 Vincenzo Librandi, <a href="/A191012/b191012.txt">Table of n, a(n) for n = 0..1000</a> %H A191012 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1). %F A191012 a(n) = n*A060884(n). %F A191012 G.f.: x*(5*x^4 + 32*x^3 + 66*x^2 + 16*x + 1)/(1-x)^6. %e A191012 a(2) = 22 is in the sequence, because x^5 + x^4 + x^3 + x^2 + x + 22 = (x+2)*(x^4 - x^3 + 3*x^2 - 5*x + 11). %p A191012 [seq(n*(n^4-n^3+n^2-n+1),n=0..25)]; %o A191012 (PARI) a(n)=((((n-1)*n+1)*n-1)*n+1)*n \\ _Charles R Greathouse IV_, Jun 17 2011 %o A191012 (Magma) [n^5 - n^4 + n^3 - n^2 + n: n in [0..30]]; // _Vincenzo Librandi_, Jun 18 2011 %Y A191012 Cf. A060884. %K A191012 easy,nonn %O A191012 0,3 %A A191012 _Franz Vrabec_, Jun 16 2011