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 A117694 #7 Jul 23 2023 06:00:25
%S A117694 1,3,15,130,1565,23331,411775,8388612,193710249,5000000005,
%T A117694 142655835311,4458050224134,151437553296133,5556003412779015,
%U A117694 218946945190429695,9223372036854775816,413620130943168382097,19673204037648268787721
%N A117694 a(n) = (n^n + n)/2.
%H A117694 G. C. Greubel, <a href="/A117694/b117694.txt">Table of n, a(n) for n = 1..380</a>
%F A117694 a(n) = (n^n + n)/2.
%F A117694 a(n) = A066068(n)/2, for n > 0.
%F A117694 E.g.f.: (1/2)*(x*exp(x) - LambertW(-x)/(1 + LambertW(-x))). - _G. C. Greubel_, Jul 23 2023
%t A117694 Table[n^n+n, {n,30}]/2
%o A117694 (Magma) [(n+n^n)/2: n in [1..30]]; // _G. C. Greubel_, Jul 23 2023
%o A117694 (SageMath) [(n+n^n)/2 for n in range(1,31)] # _G. C. Greubel_, Jul 23 2023
%Y A117694 Cf. A066068.
%K A117694 nonn
%O A117694 1,2
%A A117694 _Alexander Adamchuk_, Apr 12 2006