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 A360876 #13 Oct 03 2024 08:05:14
%S A360876 3,9,39,177,783,3369,14199,58977,242463,989529,4017159,16245777,
%T A360876 65514543,263652489,1059392919,4251920577,17050729023,68332056249,
%U A360876 273715645479,1096024843377,4387586157903,17560804984809,70274600998839,281192547174177,1125052618233183
%N A360876 Number of connected dominating sets in the 2 X n rook graph.
%H A360876 Andrew Howroyd, <a href="/A360876/b360876.txt">Table of n, a(n) for n = 1..1000</a>
%H A360876 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (8,-19,12).
%F A360876 a(n) = 8*a(n-1) - 19*a(n-2) + 12*a(n-3) for n > 3.
%F A360876 G.f.: 3*x*(1 - 5*x + 8*x^2)/((1 - x)*(1 - 3*x)*(1 - 4*x)).
%t A360876 LinearRecurrence[{8, -19, 12}, {3, 9, 39}, 30] (* _Paolo Xausa_, Oct 03 2024 *)
%o A360876 (PARI) Vec(3*(1 - 5*x + 8*x^2)/((1 - x)*(1 - 3*x)*(1 - 4*x)) + O(x^25))
%Y A360876 Row 2 of A360875.
%Y A360876 Cf. A360874.
%K A360876 nonn,easy
%O A360876 1,1
%A A360876 _Andrew Howroyd_, Feb 24 2023