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 A288836 #32 May 09 2025 13:35:09
%S A288836 18,189,1296,7290,36450,168399,734832,3070548,12400290,48715425,
%T A288836 187067232,704690766,2611501074,9542023155,34437376800,122941435176,
%U A288836 434685788658,1523724783237,5299912289520,18305618105250,62824881337218,214364018189079,727538485975056
%N A288836 a(n) = (1/3!)*3^(n+1)*(n+5)*(n+1)*(n).
%H A288836 Harvey P. Dale, <a href="/A288836/b288836.txt">Table of n, a(n) for n = 1..1000</a>
%H A288836 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (12, -54, 108, -81).
%F A288836 O.g.f.: z*3^2*(2-3*z)/(1-3*z)^4.
%F A288836 a(n) = -A287768(n+5,6).
%t A288836 LinearRecurrence[{12,-54,108,-81},{18,189,1296,7290},30] (* _Harvey P. Dale_, May 09 2025 *)
%Y A288836 Column k=6 of A287768.
%Y A288836 Cf. A288834, A288835, A288838.
%K A288836 nonn
%O A288836 1,1
%A A288836 _Gregory Gerard Wojnar_, Jun 17 2017