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 A017631 #13 Jul 08 2025 06:14:14
%S A017631 729,9261,35937,91125,185193,328509,531441,804357,1157625,1601613,
%T A017631 2146689,2803221,3581577,4492125,5545233,6751269,8120601,9663597,
%U A017631 11390625,13312053,15438249,17779581,20346417
%N A017631 a(n) = (12*n+9)^3.
%H A017631 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A017631 G.f. 27*(27+235*x+121*x^2+x^3)/(x-1)^4. a(n) = 27*A016839(n). - _R. J. Mathar_, Dec 03 2015
%t A017631 (12*Range[0,30]+9)^3 (* or *) LinearRecurrence[{4,-6,4,-1},{729,9261,35937,91125},30] (* _Harvey P. Dale_, Apr 06 2016 *)
%o A017631 (PARI) a(n) = (12*n+9)^3; \\ _Altug Alkan_, Dec 03 2015
%K A017631 nonn,easy
%O A017631 0,1
%A A017631 _N. J. A. Sloane_