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 A028684 #15 Jul 14 2025 00:24:58
%S A028684 1,462,108002664,12244181663697984,671907296255880840847211520,
%T A028684 17845802448787704188422900898268569763840,
%U A028684 229407835408995110669430829173445733902175228551055278080,1427334550066488576237160094041582026191840875706260743124583853079375380480
%N A028684 Pseudo Galois numbers for d=22.
%H A028684 Vincenzo Librandi, <a href="/A028684/b028684.txt">Table of n, a(n) for n = 0..27</a>
%F A028684 a(n) = 22^n * Product_{k=0..n-1} (22^n - 22^k).
%F A028684 a(n) ~ c * 22^(n^2+n), where c = Product_{k>=1} (1 - 1/22^k) = 0.952479533281... . - _Amiram Eldar_, Jul 14 2025
%t A028684 FoldList[ #1*22^#2 (22^#2-1)&, 1, Range[ 20 ] ]
%t A028684 a[n_] := 22^n * Product[22^n - 22^k, {k, 0, n-1}]; Array[a, 8, 0] (* _Amiram Eldar_, Jul 14 2025 *)
%o A028684 (PARI) a(n) = 22^n * prod(k = 0, n-1, 22^n - 22^k); \\ _Amiram Eldar_, Jul 14 2025
%Y A028684 Cf. A028668, A028670, A028671, A028672, A028674, A028676, A028677, A028678, A028680, A028682, A028683, A028686.
%K A028684 nonn
%O A028684 0,2
%A A028684 _Olivier Gérard_