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 A028685 #21 Jul 12 2025 08:33:58
%S A028685 1,506,141331872,20920469730667584,1638296742744745305180456960,
%T A028685 67868907839960050279986415163868117749760,
%U A028685 1487321615877089920298398794877451264100990832314711736320
%N A028685 Galois numbers for p=23; order of group AGL(n,23).
%H A028685 Vincenzo Librandi, <a href="/A028685/b028685.txt">Table of n, a(n) for n = 0..26</a>
%H A028685 <a href="/index/Gre#groups">Index entries for sequences related to groups</a>.
%F A028685 a(n) = 23^n * Product_{k=0..n-1} (23^n - 23^k).
%F A028685 a(n) ~ c * 23^(n^2+n), where c = Product_{k>=1} (1 - 1/23^k) = 0.954631535623... . - _Amiram Eldar_, Jul 12 2025
%t A028685 FoldList[ #1*23^#2 (23^#2-1)&, 1, Range[ 20 ] ]
%t A028685 a[n_] := 23^n * Product[23^n - 23^k, {k, 0, n-1}]; Array[a, 7, 0] (* _Amiram Eldar_, Jul 12 2025 *)
%o A028685 (PARI) a(n) = 23^n * prod(k = 0, n-1, 23^n - 23^k); \\ _Amiram Eldar_, Jul 12 2025
%Y A028685 Cf. A028365, A028665, A028667, A028669, A028673, A028675, A028679, A028681.
%K A028685 nonn
%O A028685 0,2
%A A028685 _Olivier Gérard_