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 A145610 #8 Mar 17 2019 02:06:21
%S A145610 2,12,20,280,2520,27720,360360,720720,4084080,15519504,5173168,
%T A145610 356948592,8923714800,80313433200,2329089562800,144403552893600,
%U A145610 13127595717600,13127595717600,485721041551200,485721041551200
%N A145610 Denominator of the polynomial A_l(x) = Sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=1.
%C A145610 For numerators and explicit examples of the polynomials see A145609.
%p A145610 A := proc(l,x) add(x^(l-d)/d,d=1..l-1) ; end: A145610 := proc(n) denom( A(2*n+1,1)) ; end: seq(A145610(n),n=1..20) ; # _R. J. Mathar_, Aug 21 2009
%t A145610 m = 1; aa = {}; Do[k = 0; Do[k = k + m^(2 r + 1 - d)/d, {d, 1, 2 r}]; AppendTo[aa, Denominator[k]], {r, 1, 30}]; aa (* _Artur Jasinski_ *)
%Y A145610 Cf. A145609 - A145640.
%K A145610 frac,nonn
%O A145610 1,1
%A A145610 _Artur Jasinski_, Oct 14 2008
%E A145610 Edited by _R. J. Mathar_, Aug 21 2009