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 A081132 #26 Sep 08 2022 08:45:09
%S A081132 1,6,54,640,9375,163296,3294172,75497472,1937102445,55000000000,
%T A081132 1711870023666,57954652913664,2120125746145771,83340051191685120,
%U A081132 3503151123046875000,156797324626531188736,7445162356977030877593
%N A081132 a(n) = (n+1)^n*binomial(n+2,2).
%C A081132 A diagonal of A081130.
%C A081132 a(n) is the sum of all the fixed points in the set of endofunctions on {1,2,...,n+1}, i.e., the functions f:{1,2,...,n+1} -> {1,2,...,n+1}. - _Geoffrey Critzer_, Sep 17 2011
%H A081132 Vincenzo Librandi, <a href="/A081132/b081132.txt">Table of n, a(n) for n = 0..300</a>
%F A081132 a(n) = (n+1)^n*binomial(n+2,2).
%e A081132 a(1) = 6 because there are four functions from {1,2} into {1,2}: (1*,1) (1*,2*) (2,1) (2,2*) and the fixed points (marked *) sum to 6.
%p A081132 seq((n+1)^n*binomial(n+2,2), n=0..20); # _G. C. Greubel_, May 18 2021
%t A081132 Table[n^n*(n+1)/2,{n,20}]
%o A081132 (Magma)[((n+1)^n*Binomial(n+2,2)): n in [0..20]]; // _Vincenzo Librandi_, Sep 21 2011
%o A081132 (Sage) [(n+1)^n*binomial(n+2,2) for n in (0..20)] # _G. C. Greubel_, May 18 2021
%Y A081132 Sequences of the form (n+m)^n*binomial(n+2,2): A081133 (m=0), this sequence (m=1), A081131 (m=2), A053507 (m=3), A081196 (m=4).
%K A081132 easy,nonn
%O A081132 0,2
%A A081132 _Paul Barry_, Mar 08 2003