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 A275213 #16 Jan 06 2023 10:53:22
%S A275213 1,1,1,1,1,2,1,5,2,12,4,32,9,94,23,289,62,910,176,2934,512,9686,1551,
%T A275213 32540,4822,110780,15266,381676,49141,1328980,160728,4669367,532890,
%U A275213 16535154,1785162,58965214,6039328,211591218,20617808,763535450,70951548,2769176514
%N A275213 The largest coefficients of the extended q-Catalan polynomials which are defined in A274886.
%H A275213 Vaclav Kotesovec, <a href="/A275213/b275213.txt">Table of n, a(n) for n = 0..100</a>
%H A275213 Peter Luschny, <a href="https://oeis.org/wiki/User:Peter_Luschny/Orbitals">Orbitals</a>
%p A275213 # Function QExtCatalan is defined in A274886.
%p A275213 seq(max(QExtCatalan(n,q)), n=0..20);
%t A275213 (* Function QExtCatalan is defined in A274886. *)
%t A275213 Table[Max[CoefficientList[QExtCatalan[n] // FunctionExpand, q]], {n,0,30}]
%o A275213 (Sage) # uses[q_ext_catalan_number]
%o A275213 # Function q_ext_catalan_number is in A274886.
%o A275213 print([max(q_ext_catalan_number(n).list()) for n in (0..41)])
%Y A275213 Cf. A274882, A274886.
%K A275213 nonn
%O A275213 0,6
%A A275213 _Peter Luschny_, Jul 20 2016