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 A097810 #26 Mar 07 2025 10:50:54
%S A097810 1,5,16,41,94,203,424,869,1762,3551,7132,14297,28630,57299,114640,
%T A097810 229325,458698,917447,1834948,3669953,7339966,14679995,29360056,
%U A097810 58720181,117440434,234880943,469761964,939524009,1879048102,3758096291
%N A097810 a(n) = 7*2^n - 3*n - 6.
%H A097810 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-5,2).
%F A097810 G.f.: (1 + x + x^2)/((1-x)^2*(1-2*x)).
%F A097810 a(n) = 2*a(n-1) + 3*n, n > 0, a(0)=1.
%F A097810 a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3).
%F A097810 From _Elmo R. Oliveira_, Mar 06 2025: (Start)
%F A097810 E.g.f.: exp(x)*(7*exp(x) - 3*(x + 2)).
%F A097810 a(n) = A131068(n+1)/2. (End)
%t A097810 s=1;lst={s};Do[s+=(s+=n)+n++;AppendTo[lst, s], {n, 1, 5!, 1}];lst (* _Vladimir Joseph Stephan Orlovsky_, Nov 15 2008 *)
%t A097810 Table[7*2^n-3n-6,{n,0,30}] (* or *) LinearRecurrence[{4,-5,2},{1,5,16},30] (* _Harvey P. Dale_, Nov 15 2011 *)
%Y A097810 Cf. A079583, A097809, A131068.
%K A097810 easy,nonn
%O A097810 0,2
%A A097810 _Paul Barry_, Aug 25 2004