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 A166153 #10 Jun 30 2023 14:29:59
%S A166153 1,-7,63,-455,3983,-29463,252511,-1902439,16043055,-122579639,
%T A166153 1020990719,-7885450503,65060930767,-506646158935,4150058281887,
%U A166153 -32522243182247,264925506967919,-2086171125173751,16921999515377215
%N A166153 a(n) = (7^n+14*(-8)^n)/15.
%H A166153 G. C. Greubel, <a href="/A166153/b166153.txt">Table of n, a(n) for n = 0..1000</a>
%H A166153 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (-1, 56).
%F A166153 a(n) = 56*a(n-2)-a(n-1), a(0)= 1, a(1)= -7, for n>1.
%F A166153 G.f.: (1-6*x)/(1+x-56*x^2).
%F A166153 a(n) = Sum_{k=0..n} A112555(n,k)*(-8)^k.
%F A166153 E.g.f.: (1/15)*(exp(7*x) + 14*exp(-8*x)). - _G. C. Greubel_, May 01 2016
%t A166153 LinearRecurrence[{-1, 56}, {1, -7}, 50] (* _G. C. Greubel_, May 01 2016 *)
%Y A166153 Cf. A112555, A166035, A166036, A166149, A166152.
%K A166153 easy,sign
%O A166153 0,2
%A A166153 _Philippe Deléham_, Oct 08 2009