A187179 - OEIS

%I #24 Oct 21 2017 21:01:49

%S 7,7,8,9,11,14,19,27,40,61,95,150,239,383,616,993,1603,2590,4187,6771,

%T 10952,17717,28663,46374,75031,121399,196424,317817,514235,832046,

%U 1346275,2178315,3524584,5702893,9227471,14930358,24157823

%N Number of nontrivial compositions of differential operations and directional derivative of the n-th order on the space R^10.

%H Ivana Jovović and Branko Malešević, <a href="http://nntdm.net/volume-23-2017/number-1/28-38/">Some enumerations of non-trivial composition of the differential operations and the directional derivative</a>, Notes on Number Theory and Discrete Mathematics, Vol. 23, 2017, No. 1, 28-38.

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,-1).

%F a(n) = A000045(n) + 6.

%F a(n) = 2*a(n-1)-a(n-3). G.f.: -x*(6*x^2+7*x-7) / ((x-1)*(x^2+x-1)). [_Colin Barker_, Dec 14 2012]

%t LinearRecurrence[{2,0,-1},{7,7,8},40] (* _Harvey P. Dale_, Apr 29 2015 *)

%Y Cf. A000045.

%K nonn,easy

%O 1,1

%A _Branko Malesevic_, Mar 06 2011