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 A373343 #13 Jun 03 2024 18:21:48
%S A373343 1,1,1,2,1,1,6,24,2,1,24,20736,373248,16,1,120,995328000,
%T A373343 189321481108517289984,12635683568857645056,2048,1
%N A373343 Array read by ascending antidiagonals: A(n,k) is the number of cyclic de Bruijn sequences of order k and alphabet of size n, with k > 0.
%C A373343 The 7th antidiagonal is too large to be included in Data.
%H A373343 D. Condon, Yuxin Wang, and E. Yang, <a href="https://arxiv.org/abs/2405.18543">De Bruijn Polyominoes</a>, arXiv:2405.18543 [math.CO], 2024. See page 5.
%H A373343 T. van Aardenne-Ehrenfest and N. G. de Brujin, <a href="https://pure.tue.nl/ws/files/3311129/597493.pdf">Circuits and Trees in Oriented Linear Graphs</a>. In: Simon Stevin 28 (1951), pp. 203-217.
%F A373343 A(n,k) = (n!)^(n^(k-1))/n^k.
%F A373343 A(n,k) = A373341(n,k)/A003992(n,k).
%e A373343 The array begins:
%e A373343 1, 1, 1, 1, ...
%e A373343 1, 1, 2, 16, ...
%e A373343 2, 24, 373248, 12635683568857645056, ...
%e A373343 ...
%t A373343 A[n_,k_]:=(n!)^(n^(k-1))/n^k; Table[A[n-k+1,k],{n,6},{k,n}]//Flatten
%Y A373343 Cf. A000012 (n=1), A000142 (k=1), A003992, A016031 (n=2), A373341 (acyclic), A373344 (antidiagonal sums).
%K A373343 nonn,tabl
%O A373343 1,4
%A A373343 _Stefano Spezia_, Jun 01 2024