cp's OEIS Frontend

A168374 a(n) = 7 * floor(n/2).

%I A168374 #23 Sep 08 2022 08:45:49
%S A168374 0,7,7,14,14,21,21,28,28,35,35,42,42,49,49,56,56,63,63,70,70,77,77,84,
%T A168374 84,91,91,98,98,105,105,112,112,119,119,126,126,133,133,140,140,147,
%U A168374 147,154,154,161,161,168,168,175,175,182,182,189,189,196,196,203,203,210
%N A168374 a(n) = 7 * floor(n/2).
%H A168374 Vincenzo Librandi, <a href="/A168374/b168374.txt">Table of n, a(n) for n = 1..1000</a>
%H A168374 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F A168374 a(n) = 7*n - a(n-1) - 7, with n>1, a(1)=0.
%F A168374 G.f.: 7*x^2/((1+x)*(1-x)^2). - _Bruno Berselli_, Sep 17 2013
%F A168374 a(n) = 7*A004526(n). - _Bruno Berselli_, Sep 17 2013
%F A168374 E.g.f.: (7/2)*(x*cosh(x) + (x - 1)*sinh(x)). - _G. C. Greubel_, Jul 19 2016
%t A168374 CoefficientList[Series[7 x/((1 + x) (1 - x)^2), {x, 0, 70}], x] (* _Vincenzo Librandi_, Sep 17 2013 *)
%t A168374 Table[7 Floor[n/2], {n, 60}] (* _Bruno Berselli_, Sep 18 2013 *)
%o A168374 (Magma) [n eq 1 select 0 else 7*n-Self(n-1)-7: n in [1..70]]; // _Vincenzo Librandi_, Sep 17 2013
%Y A168374 Cf. A004526, A008589.
%K A168374 nonn,easy,less
%O A168374 1,2
%A A168374 _Vincenzo Librandi_, Nov 24 2009
%E A168374 New definition by _Bruno Berselli_, Sep 18 2013