A030429 - OEIS

%I #19 Sep 30 2025 03:26:33

%S 1,2,7,26,115,596,3331,19100,110329,638540,3697405,21411974,124001893,

%T 718129334,4158891979,24085338398,139485124807,807798504728,

%U 4678193659303,27092766081872,156902006957821,908664686131472,5262338754215377,30475718476587146,176493658056602185

%N a(n+2) = 7*a(n+1) - 7*a(n) - 9*n; a(n+4) = 9*a(n+3) - 22*a(n+2) + 21*a(n+1) - 7*a(n).

%C Hypothetical numbers of terms in general expressions for Lovelock tensors. Hypothetical extension of sequence A006373. - C. C. Briggs (ccb104(AT)psu.edu)

%H C. C. Briggs, <a href="https://arxiv.org/abs/gr-qc/9808050">Some Possible Features of General Expressions for Lovelock Tensors ...</a>, arXiv:gr-qc/9808050, 2000.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (9,-22,21,-7).

%F G.f.: (1-7*x+11*x^2-14*x^3)/((1-7*x+7*x^2)*(x-1)^2).

%F a(n) = 2*(23*A030240(n)-133*A030240(n-1)) -9*n -45. - _R. J. Mathar_, Mar 14 2011

%t LinearRecurrence[{9,-22,21,-7},{1,2,7,26},30] (* _Harvey P. Dale_, Oct 12 2015 *)

%Y Cf. A006373.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_

%E More terms from _Jason Yuen_, Sep 29 2025