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 A168390 #33 Mar 04 2024 01:12:26
%S A168390 1,9,9,17,17,25,25,33,33,41,41,49,49,57,57,65,65,73,73,81,81,89,89,97,
%T A168390 97,105,105,113,113,121,121,129,129,137,137,145,145,153,153,161,161,
%U A168390 169,169,177,177,185,185,193,193,201,201,209,209,217,217,225,225,233,233
%N A168390 a(n) = 1 + 8*floor(n/2).
%H A168390 Vincenzo Librandi, <a href="/A168390/b168390.txt">Table of n, a(n) for n = 1..1000</a>
%H A168390 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F A168390 a(n) = 8*n - a(n-1) - 6, with n>1, a(1)=1.
%F A168390 a(1)=1, a(2)=9, a(3)=9; for n>3, a(n) = a(n-1) + a(n-2) - a(n-3). - _Harvey P. Dale_, Jul 28 2012
%F A168390 G.f.: x*(1 + 8*x - x^2)/((1+x)*(x-1)^2). - _Vincenzo Librandi_, Sep 18 2013
%F A168390 a(n) = A168381(n) - 1 = A168378(n) - 2. - _Bruno Berselli_, Sep 18 2013
%F A168390 E.g.f.: (2 - exp(x) + (4*x - 1)*exp(2*x))*exp(-x). - _G. C. Greubel_, Jul 19 2016
%t A168390 RecurrenceTable[{a[1]==1,a[n]==8n-a[n-1]-6},a,{n,60}] (* or *) LinearRecurrence[{1,1,-1},{1,9,9},60] (* or *) With[{c=Table[8n+1,{n,0,40}]},Rest[Riffle[c,c]]] (* _Harvey P. Dale_, Jul 28 2012 *)
%t A168390 Table[1 + 8 Floor[n/2], {n, 60}] (* _Bruno Berselli_, Sep 18 2013 *)
%t A168390 CoefficientList[Series[(1 + 8 x - x^2)/((1 + x) (x - 1)^2), {x, 0, 70}], x] (* _Vincenzo Librandi_, Sep 18 2013 *)
%o A168390 (Magma) [1+8*Floor(n/2): n in [1..70]]; // _Vincenzo Librandi_, Sep 18 2013
%Y A168390 Cf. A017077, A168378, A168381.
%K A168390 nonn,easy
%O A168390 1,2
%A A168390 _Vincenzo Librandi_, Nov 24 2009
%E A168390 New definition by _Vincenzo Librandi_, Sep 18 2013