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 A341576 #22 Nov 08 2023 11:32:22
%S A341576 1,1,1,3,7,16,46,149,520,1977,8136,35878,168501,838945,4409957,
%T A341576 24385913,141412615,857611640,5426144190,35739397739,244573978100,
%U A341576 1735854397529,12757309001220,96941738970956,760649367654461,6155205917196409,51308394497243469
%N A341576 a(n) = Sum_{k=0..n} U_k((n-k)/2) where U_n(x) is a Chebyshev polynomial of the 2nd kind.
%H A341576 <a href="/index/Ch#Cheby">Index entries for sequences related to Chebyshev polynomials.</a>
%t A341576 a[n_] := Sum[ChebyshevU[k, (n - k)/2], {k, 0, n}]; Array[a, 27, 0] (* _Amiram Eldar_, Mar 08 2021 *)
%o A341576 (PARI) a(n) = sum(k=0, n, polchebyshev(k, 2, (n-k)/2));
%o A341576 (Python)
%o A341576 from fractions import Fraction
%o A341576 from sympy import chebyshevu
%o A341576 def A341576(n): return sum(chebyshevu(k,Fraction(n-k,2)) for k in range(n+1)) # _Chai Wah Wu_, Nov 08 2023
%Y A341576 Cf. A101125, A323613.
%K A341576 nonn
%O A341576 0,4
%A A341576 _Seiichi Manyama_, Mar 08 2021