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 A028672 #14 Jul 14 2025 00:25:24
%S A028672 1,90,891000,890109000000,89001998910000000000,
%T A028672 890011088900109000000000000000,
%U A028672 890010198889020099891000000000000000000000,89001010988800021098899001090000000000000000000000000000,890010100987899112108987901010099891000000000000000000000000000000000000
%N A028672 Pseudo Galois numbers for d=10.
%H A028672 Vincenzo Librandi, <a href="/A028672/b028672.txt">Table of n, a(n) for n = 0..31</a>
%F A028672 a(n) = 10^n * Product_{k=0..n-1} (10^n - 10^k).
%F A028672 a(n) ~ c * 10^(n^2+n), where c = A132038. - _Amiram Eldar_, Jul 13 2025
%t A028672 FoldList[ #1*10^#2 (10^#2-1)&, 1, Range[ 20 ] ]
%t A028672 a[n_] := 10^n * Product[10^n - 10^k, {k, 0, n-1}]; Array[a, 9, 0] (* _Amiram Eldar_, Jul 13 2025 *)
%o A028672 (PARI) a(n) = 10^n * prod(k = 0, n-1, 10^n - 10^k); \\ _Amiram Eldar_, Jul 13 2025
%Y A028672 Cf. A028668, A028670, A028671, A028674, A028676, A028677, A028678, A028680, A028682, A028683, A028684, A028686.
%Y A028672 Cf. A132038.
%K A028672 nonn
%O A028672 0,2
%A A028672 _Olivier Gérard_