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 A089539 #18 Mar 30 2024 16:14:45
%S A089539 4,4,9,25,121,721,5041,40321,362885,3628801,39916803,479001617,
%T A089539 6227020801,87178291201,1307674368007,20922789888002,355687428096003,
%U A089539 6402373705728023,121645100408832001,2432902008176640001,51090942171709440011,1124000727777607680029,25852016738884976640003
%N A089539 a(n) is the least semiprime > n!.
%F A089539 a(n) = n! + A085747(n).
%t A089539 lsn[n_]:=Module[{sp=n!+1},While[PrimeOmega[sp]!=2,sp++];sp]; Array[lsn,25] (* _Harvey P. Dale_, Mar 30 2024 *)
%Y A089539 Cf. A001358, A085747, A089538, A089540, A089541, A089542.
%K A089539 nonn
%O A089539 1,1
%A A089539 _Ray Chandler_, Nov 09 2003
%E A089539 Better name, more terms from _Jinyuan Wang_, Jul 31 2021