login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(n) = -(n - 4)*(n - 5)*(n - 12)/6.
4

%I #23 Oct 02 2018 08:52:03

%S 2,5,8,10,10,7,0,-12,-30,-55,-88,-130,-182,-245,-320,-408,-510,-627,

%T -760,-910,-1078,-1265,-1472,-1700,-1950,-2223,-2520,-2842,-3190,

%U -3565,-3968,-4400,-4862,-5355,-5880,-6438,-7030,-7657,-8320,-9020,-9758,-10535,-11352

%N a(n) = -(n - 4)*(n - 5)*(n - 12)/6.

%C Essentially the same as A111396.

%C The coefficient of x^(n-6) of the Polynomial B_n(x) defined in A135929.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4, -6, 4, -1).

%F a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).

%F G.f.: x^6*(2 - 3*x)/(x - 1)^4.

%F a(n) = -A111396(n-12) for n > 11. - _Bruno Berselli_, Oct 02 2018

%t LinearRecurrence[{4,-6,4,-1},{2,5,8,10},50] (* _Harvey P. Dale_, May 27 2012 *)

%Y Cf. A135929, A137276.

%K sign,easy

%O 6,1

%A _Jamel Ghanouchi_, Nov 06 2009

%E Minor edits by _N. J. A. Sloane_, Nov 09 2009

%E Definition simplified, sequence extended by _R. J. Mathar_, Nov 12 2009