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 A259926 #33 Sep 08 2022 08:46:13
%S A259926 0,8,486,49152,7812500,1813985280,581334062442,246290604621824,
%T A259926 133417453597332552,90000000000000000000,74002499442581601012110,
%U A259926 72872109936441607122321408,84676920178401799992368876316,114656931713301654695784797437952,178967655284025147557258605957031250
%N A259926 a(n) = n^(2*n) - n^(2*n - 1).
%F A259926 a(n) = A062206(n) - A085524(n).
%F A259926 a(n) = n^A005843(n) - n^A005408(n-1).
%F A259926 a(n) = n! * [x^n] LambertW(-n*x)^2 / (1 + LambertW(-n*x)). - _Ilya Gutkovskiy_, Mar 24 2020
%t A259926 Table[n^(2 n) - n^(2 n - 1), {n, 15}]
%t A259926 Array[#^(2 #) - #^(2 # - 1)&, 15] (* _Vincenzo Librandi_, Jul 10 2015 *)
%o A259926 (PARI) vector(20, n, n^(2*n) - n^(2*n-1)) \\ _Michel Marcus_, Jul 09 2015
%o A259926 (Sage) [n**(2*n) - n**(2*n - 1) for n in range(1, 20)] # _Anders Hellström_, Jul 10 2015
%o A259926 (Magma) [n^(2*n) - n^(2*n - 1): n in [1..20]]; // _Vincenzo Librandi_, Jul 10 2015
%Y A259926 Cf. A005408, A005843, A062206, A085524, A086815.
%K A259926 nonn
%O A259926 1,2
%A A259926 _Ilya Gutkovskiy_, Jul 09 2015