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 A152291 #29 Jun 25 2023 18:21:03
%S A152291 1,1,1,4,5,36,49,512,729,10000,14641,248832,371293,7529536,11390625,
%T A152291 268435456,410338673,11019960576,16983563041,512000000000,
%U A152291 794280046581,26559922791424,41426511213649,1521681143169024,2384185791015625
%N A152291 a(n) = (n+1)^floor((n-1)/2).
%F A152291 Row sums of A152290 at q=-1: a(n) = Sum_{k=0..n(n-1)/2} A152290(n,k)*(-1)^k.
%F A152291 a(n) = denominator((-3+(-1)^n)*((1-sqrt(1+n+1/(1+n)))^n-(1+sqrt(1+n+1/(1+n)))^n)/(8*sqrt(1+n+1/(1+n)))). - _Gerry Martens_, May 31 2015
%o A152291 (PARI) a(n)=(n+1)^floor((n-1)/2)
%o A152291 (PARI) vector(30, n, n--; (n+1)^((n-1)\2)) \\ _Michel Marcus_, Jun 01 2015
%o A152291 (Magma) [(n+1)^((n-1) div 2): n in [0..30]]; // _Vincenzo Librandi_, May 31 2015
%Y A152291 Cf. A152290, A000272.
%Y A152291 This is for Coxeter type A what A078707 is for Coxeter type B.
%K A152291 nonn
%O A152291 0,4
%A A152291 _Paul D. Hanna_, Dec 02 2008