This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A030429 #13 Jul 08 2025 19:33:07
%S A030429 1,2,7,26,115,596,3331,19100,110329,638540,3697405,21411974,124001893,
%T A030429 718129334,4158891979,24085338398,139485124807,807798504728,
%U A030429 4678193659303,27092766081872,156902006957821
%N A030429 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 A030429 Hypothetical numbers of terms in general expressions for Lovelock tensors. Hypothetical extension of sequence A006373 - C. C. Briggs (ccb104(AT)psu.edu)
%H A030429 C. C. Briggs, <a href="http://arXiv.org/abs/gr-qc/9808050">Some Possible Features of General Expressions for Lovelock Tensors ...</a>
%H A030429 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (9,-22,21,-7).
%F A030429 Expansion of (1-7*x+11*x^2-14*x^3)/((1-7*x+7*x^2)*(x-1)^2).
%F A030429 a(n) = 2*(23*A030240(n)-133*A030240(n-1)) -9*n -45. - R. J. Mathar, Mar 14 2011
%t A030429 LinearRecurrence[{9,-22,21,-7},{1,2,7,26},30] (* _Harvey P. Dale_, Oct 12 2015 *)
%Y A030429 Cf. A006373.
%K A030429 nonn
%O A030429 0,2
%A A030429 _N. J. A. Sloane_