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 A263615 #9 Feb 07 2024 19:04:06
%S A263615 2,4,8,12,20,28,44,59,89,115,167,209,293,357,485,578,764,894,1154,
%T A263615 1330,1682,1914,2378,2677,3275,3653,4409,4879,5819,6395,7547,8244,
%U A263615 9638,10472,12140,13128,15104,16264,18584,19935,22637,24199,27323,29117,32705,34753,38849,41174,45824,48450
%N A263615 Partial sums of A263614 starting at n=2.
%H A263615 Colin Barker, <a href="/A263615/b263615.txt">Table of n, a(n) for n = 2..1000</a>
%H A263615 G. J. Simmons, <a href="/A002778/a002778_2.pdf">Palindromic powers</a>, J. Rec. Math., 3 (No. 2, 1970), 93-98. [Annotated scanned copy]
%H A263615 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (1,4,-4,-6,6,4,-4,-1,1).
%F A263615 From _Colin Barker_, Oct 26 2015: (Start)
%F A263615 a(n) = (2*n*(3*n^3-14*n^2+147*n+272)+(4*n^3-30*n^2+128*n-27)*(-1)^n-741)/768.
%F A263615 G.f.: x^2*(x^7-4*x^5-4*x^4+4*x^3+4*x^2-2*x-2) / ((x-1)^5*(x+1)^4).
%F A263615 (End)
%t A263615 LinearRecurrence[{1,4,-4,-6,6,4,-4,-1,1},{2,4,8,12,20,28,44,59,89},50] (* _Harvey P. Dale_, Feb 07 2024 *)
%o A263615 (PARI) a(n) = (2*n*(3*n^3-14*n^2+147*n+272)+(4*n^3-30*n^2+128*n-27)*(-1)^n-741)/768 \\ _Colin Barker_, Oct 26 2015
%o A263615 (PARI) Vec(x^2*(x^7-4*x^5-4*x^4+4*x^3+4*x^2-2*x-2)/((x-1)^5*(x+1)^4) + O(x^100)) \\ _Colin Barker_, Oct 26 2015
%Y A263615 Cf. A263614.
%K A263615 nonn,base,easy
%O A263615 2,1
%A A263615 _N. J. A. Sloane_, Oct 23 2015