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 A084857 #12 Jan 03 2025 17:44:18
%S A084857 0,1,10,48,176,560,1632,4480,11776,29952,74240,180224,430080,1011712,
%T A084857 2351104,5406720,12320768,27852800,62521344,139460608,309329920,
%U A084857 682622976,1499463680,3279945728,7147094016,15518924800,33587986432,72477573120,155960999936
%N A084857 Inverse binomial transform of n^2*3^(n-1).
%C A084857 Binomial transform of octagonal numbers A000567. Inverse binomial transform of A069996.
%H A084857 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,-12,8).
%F A084857 a(n) = n*(3*n - 1)*2^(n - 2).
%F A084857 O.g.f.: -x*(1+4*x)/(-1+2*x)^3. - _R. J. Mathar_, Apr 02 2008
%t A084857 LinearRecurrence[{6,-12,8},{0,1,10},30] (* _Harvey P. Dale_, Dec 28 2019 *)
%Y A084857 Cf. A000567, A069996.
%K A084857 easy,nonn
%O A084857 0,3
%A A084857 _Paul Barry_, Jun 09 2003