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 A112289 #12 Aug 17 2019 03:25:12
%S A112289 1,1,6,33,4200,4192200,1705200,77892963984,10086416728304192640,
%T A112289 126556188275836361347200,451535899566923284351392000,
%U A112289 1253032399528279799996000622278320876800
%N A112289 Denominator of sum{k=1 to n} 1/s(n,k), where s(n,k) is an unsigned Stirling number of the first kind.
%e A112289 a(4) = 33, the denominator of 1/6 + 1/11 + 1/6 + 1 = 47/33.
%e A112289 The first few fractions are: 1, 2, 11/6, 47/33, 4999/4200.
%p A112289 with(combinat): a:=n->denom(sum(1/abs(stirling1(n,k)),k=1..n)): seq(a(n),n=1..14); # _Emeric Deutsch_, Sep 02 2005
%t A112289 f[n_] := Sum[1/Abs[StirlingS1[n, k]], {k, n}]; Table[Denominator[f[n]], {n, 15}] (* _Ray Chandler_, Sep 02 2005 *)
%o A112289 (PARI) a(n) = denominator(sum(k=1, n, 1/abs(stirling(n,k,1)))); \\ _Michel Marcus_, Aug 17 2019
%Y A112289 Cf. A112288.
%K A112289 nonn,frac
%O A112289 1,3
%A A112289 _Leroy Quet_, Sep 01 2005
%E A112289 Extended by _Emeric Deutsch_ and _Ray Chandler_, Sep 02 2005