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 A290363 #16 Oct 14 2023 11:32:10
%S A290363 0,1,30,424,3357,17836,71769,236093,667335,1676364,3832477,8113347,
%T A290363 16112746,30319341,54481246,94072398,156878210,253719339,399333792,
%U A290363 613438978,921996699,1358705458,1966745847,2800806163,3929416785,5437623230,7430029191,10034242245
%N A290363 Number of 9-leaf rooted trees with n levels.
%H A290363 Alois P. Heinz, <a href="/A290363/b290363.txt">Table of n, a(n) for n = 0..1000</a>
%H A290363 B. A. Huberman and T. Hogg, <a href="https://doi.org/10.1016/0167-2789(86)90308-1">Complexity and adaptation</a>, Evolution, games and learning (Los Alamos, N.M., 1985). Phys. D 22 (1986), no. 1-3, 376-384.
%H A290363 <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>
%H A290363 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (9,-36,84,-126,126,-84,36,-9,1).
%F A290363 G.f.: -(8*x^6+135*x^5+493*x^4+537*x^3+190*x^2+21*x+1)*x / (x-1)^9.
%F A290363 a(n) = (1385*n^8 +1124*n^7 +4018*n^6 +6776*n^5 +7945*n^4 +9716*n^3 +6812*n^2 +2544*n)/8!.
%p A290363 a:= n-> (((((((1385*n+1124)*n+4018)*n+6776)*n+7945)*n
%p A290363 +9716)*n+6812)*n+2544)*n/8!:
%p A290363 seq(a(n), n=0..40);
%t A290363 CoefficientList[Series[-(8*x^6 + 135*x^5 + 493*x^4 + 537*x^3 + 190*x^2 + 21*x + 1)*x/(x - 1)^9, {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Oct 14 2023 *)
%Y A290363 Row n=9 of A290353.
%K A290363 nonn,easy
%O A290363 0,3
%A A290363 _Alois P. Heinz_, Jul 28 2017