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 A016249 #22 May 14 2023 12:45:47
%S A016249 1,16,185,1880,17841,162336,1435945,12448360,106312481,897579056,
%T A016249 7510186905,62388376440,515255179921,4235078618176,34671889197065,
%U A016249 282913935338120,2302083235036161,18688068146607696,151404361037090425,1224533599346325400,9889359772117817201
%N A016249 Expansion of 1/((1-x)*(1-7*x)*(1-8*x)).
%H A016249 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (16,-71,56).
%F A016249 a(0)=1, a(1)=16, a(n) = 15*a(n-1) - 56*a(n-2) + 1. - _Vincenzo Librandi_, Feb 10 2011
%t A016249 Table[(3*2^(3*n + 4) - 7^(n + 2) + 1)/42, {n, 40}] (* or *) CoefficientList[Series[1/((1 - z) (1 - 7*z) (1 - 8*z)), {z, 0, 40}], z] (* _Vladimir Joseph Stephan Orlovsky_, Jul 21 2011 *)
%t A016249 LinearRecurrence[{16,-71,56},{1,16,185},30] (* _Harvey P. Dale_, May 14 2023 *)
%o A016249 (PARI) Vec(1/((1-x)*(1-7*x)*(1-8*x))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012
%Y A016249 Cf. A016218, A016228, A016241.
%K A016249 nonn,easy
%O A016249 0,2
%A A016249 _N. J. A. Sloane_