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 A003308 #12 Aug 01 2022 08:21:45
%S A003308 2,2,6,32,250,2592,33614,524288,9565938,200000000,4715895382,
%T A003308 123834728448,3584320788074,113387824750592,3892390136718750,
%U A003308 144115188075855872,5724846103019631586,242879062193188503552
%N A003308 a(n) = 2*n^(n-2).
%C A003308 When n >=2, right side of binomial sum n-> Sum_{i=1..n-1} ( i^(n-i-1) * (n-i)^(i-1) *binomial(n, i) ). - Yong Kong (ykong(AT)curagen.com), Dec 28 2000
%D A003308 A. P. Prudnikov, Yu. A. Brychkov and O.I. Marichev, "Integrals and Series", Volume 1: "Elementary Functions", Chapter 4: "Finite Sums", New York, Gordon and Breach Science Publishers, 1986-1992, Eq. (4.2.2.38)
%H A003308 G. C. Greubel, <a href="/A003308/b003308.txt">Table of n, a(n) for n = 1..250</a>
%F A003308 a(n) = 2*n^(n-2).
%F A003308 a(n) = 2 * A000272(n).
%F A003308 E.g.f.: (-2)*Integral_{t=0..x} LambertW(-t)/t dt = (-1)*LambertW(-x) * (LambertW(-x) + 2). - _G. C. Greubel_, Jul 31 2022
%t A003308 Table[2*n^(n-2), {n,20}] (* _Harvey P. Dale_, Sep 18 2021 *)
%o A003308 (Magma) [2*n^(n-2): n in [1..30]]; // _G. C. Greubel_, Jul 31 2022
%o A003308 (SageMath) [2*n^(n-2) for n in (1..30)] # _G. C. Greubel_, Jul 31 2022
%Y A003308 Cf. A000272.
%K A003308 nonn
%O A003308 1,1
%A A003308 Joseph Moser (jmoser(AT)wcupa.edu)