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%I #27 Sep 08 2022 08:45:49
%S 0,6,6,12,12,18,18,24,24,30,30,36,36,42,42,48,48,54,54,60,60,66,66,72,
%T 72,78,78,84,84,90,90,96,96,102,102,108,108,114,114,120,120,126,126,
%U 132,132,138,138,144,144,150,150,156,156,162,162,168,168,174,174,180,180
%N a(n) = 6 * floor( n/2 ).
%H Vincenzo Librandi, <a href="/A168328/b168328.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1)
%F a(n) = 6*n - a(n-1) - 6 for n>1, a(1)=0.
%F G.f.: 6*x^2/((1+x)*(1-x)^2). - _Bruno Berselli_, Sep 17 2013
%F a(n) = 6*A004526(n). _Bruno Berselli_, Sep 17 2013
%F E.g.f.: 3*(x*cosh(x) + (x - 1)*sinh(x)). - _G. C. Greubel_, Jul 18 2016
%t Table[6 Floor[n/2], {n, 70}] (* _Bruno Berselli_, Sep 18 2013 *)
%o (Magma) [n eq 1 select 0 else 6*n-Self(n-1)-6: n in [1..70]]; // _Vincenzo Librandi_, Sep 17 2013
%Y Cf. A004526, A008588.
%K nonn,easy,less
%O 1,2
%A _Vincenzo Librandi_, Nov 23 2009
%E G.f. adapted to the offset by _Vincenzo Librandi_, Sep 17 2013
%E New definition by _Bruno Berselli_, Sep 18 2013