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 A071541 #13 Jul 27 2024 09:41:37
%S A071541 6,43,336,2932,26870,252756,2409731,23169860,224059958,2175865640
%N A071541 Number of k's less than or equal to 10^n such that there are middle divisors of k (A071562).
%F A071541 a(n) = 10^n - A071540(n). - _Amiram Eldar_, Jul 27 2024
%t A071541 f[n_] := Plus @@ Select[ Divisors[n], Sqrt[n/2] <= # < Sqrt[n*2] &]; s = 0; k = 0; Do[ While[k < 10^n, k++; If[ f[k] != 0, s++ ]]; Print[s], {n, 1, 7}]
%o A071541 (PARI) lista(nmax) = {my(c = 0, pow = 10); for(k = 1, 10^nmax, if(sumdiv(k, d, if(d^2 >= k/2 && d^2 < 2*k, d, 0)) > 0, c++); if(k == pow, print1(c, ", "); pow *= 10));} \\ _Amiram Eldar_, Jul 27 2024
%Y A071541 Cf. A071090, A071540, A071562.
%K A071541 nonn,hard,more
%O A071541 1,1
%A A071541 _Robert G. Wilson v_, May 31 2002
%E A071541 a(8) from _Sean A. Irvine_, Jul 25 2024
%E A071541 a(9)-a(10) from _Amiram Eldar_, Jul 27 2024