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 A234252 #10 Jun 06 2021 06:01:42
%S A234252 -1,1,0,23,112,2637,28928,705259,12021504,337390073,7752749056,
%T A234252 252186614847,7261683740672,271082082053317,9359536638984192,
%U A234252 396049017137512403,15920162462882529280,754792662169555947633,34587513064809080815616,1818644980834260579498343
%N A234252 a(n) = ((n-1)^(n+1) + (-1)^n*(n+1)^(n-1))/(n^2).
%C A234252 a(2n) = A233446(n) = ((2n-1)^(2n+1) + (2n+1)^(2n-1))/(2n)^2 = A154682(n)/(2n)^2 for n > 0.
%F A234252 a(n) = ((n-1)^(n+1) + (-1)^n*(n+1)^(n-1))/(n^2).
%t A234252 Table[((m-1)^(m+1)+(-1)^m*(m+1)^(m-1))/(m^2),{m,1,20}]
%o A234252 (PARI) a(n) = ((n-1)^(n+1) + (-1)^n*(n+1)^(n-1))/n^2; \\ _Michel Marcus_, Jun 06 2021
%Y A234252 Cf. A154682, A233446.
%K A234252 sign
%O A234252 1,4
%A A234252 _Alexander Adamchuk_, Dec 22 2013