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 A070843 #13 Sep 30 2021 13:17:44
%S A070843 9,99,996,9996,99990,999570,9999990,99981420,999068070,9592993410
%N A070843 Largest n-digit number with exactly n distinct prime divisors. There are no further terms.
%C A070843 Primes counted without multiplicity. - _Harvey P. Dale_, Sep 30 2021
%e A070843 a(4) = 9996 with the prime divisors 2,3,7 and 17.
%t A070843 Do[k = 10^n - 1; While[Length[FactorInteger[k]] != n, k-- ]; Print[k], {n, 1, 10}] (* _Ryan Propper_, Nov 05 2005 *)
%t A070843 lnpd[n_]:=Module[{k=10^n-1},While[PrimeNu[k]!=n,k--];k]; Array[lnpd,10] (* _Harvey P. Dale_, Sep 30 2021 *)
%Y A070843 Cf. A070842.
%K A070843 base,nonn,fini,full
%O A070843 1,1
%A A070843 _Amarnath Murthy_, May 12 2002
%E A070843 More terms from _Rick L. Shepherd_, May 14 2002
%E A070843 a(10) from _Ryan Propper_, Nov 05 2005
%E A070843 Edited by _Ray Chandler_, Feb 15 2009
%E A070843 Definition clarified by _Harvey P. Dale_, Sep 30 2021