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 A055869 #48 Jan 25 2023 09:54:17
%S A055869 1,5,37,369,4651,70993,1273609,26269505,612579511,15937424601,
%T A055869 457696700077,14381984674225,490839666661891,18080919199832609,
%U A055869 715027614225987601,30214447801957316865,1358671297852359767791,64780942222614703957417,3264460344339686410876021
%N A055869 a(n) = (n+1)^n - n^n.
%C A055869 Number of functions f:[n]->[n+1] such that some x in [n] maps to n+1.
%C A055869 Number of switching generators for a power polyadic n-context ({1..k}, ..., {1..k}, <>) with n=k [Theorems 5 and 6, page 81, in Ignatov]. - _Dmitry I. Ignatov_, Nov 23 2022
%H A055869 G. C. Greubel, <a href="/A055869/b055869.txt">Table of n, a(n) for n = 1..385</a>
%H A055869 D. I. Ignatov, <a href="https://doi.org/10.1016/j.dam.2017.12.032">On closure operators related to maximal tricliques in tripartite hypergraphs</a>, Discrete Appl. Math., 249 (2018), 74-84.
%H A055869 D. I. Ignatov, <a href="https://github.com/dimachine/SwitchingGenerators">Supporting iPython code for enumeration of switching generators of power polyadic n-contexts for n=k<6</a>, GitHub repository.
%F A055869 E.g.f.: W(-x)*(x-1)/((1+W(-x))*x), W(x) principal branch of Lambert's function.
%F A055869 a(n) = Sum_{m=1..n} A055864(n, m).
%F A055869 a(n) = Sum_{i=0..n-1} n^i*C(n, i). - _Olivier Gérard_, Jun 26 2001
%F A055869 With interpolated zeros, ceiling(n/2)^floor(n/2) - floor(n/2)^floor(n/2). - _Paul Barry_, Jul 13 2005
%F A055869 a(n) = Sum_{k=1..n} (-1)^(n-k)*k!*Stirling2(n,k)*binomial(n+k-1,n). - _Vladimir Kruchinin_, Sep 20 2015
%t A055869 Table[(n+1)^n-n^n,{n,40}] (* _Vladimir Joseph Stephan Orlovsky_, Nov 20 2009 *)
%o A055869 (PARI) vector(20, n, (n+1)^n - n^n) \\ _Michel Marcus_, Jan 10 2015
%o A055869 (Magma) [(n+1)^n - n^n: n in [1..40]]; // _Vincenzo Librandi_, Jan 11 2015
%Y A055869 Row sums of triangle A055864.
%Y A055869 Cf. A055864, A055858, A045531.
%K A055869 nonn,easy
%O A055869 1,2
%A A055869 _Wolfdieter Lang_, Jun 20 2000
%E A055869 More terms from _Vincenzo Librandi_, Jan 11 2015