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 A025942 #14 Jul 08 2025 17:44:05
%S A025942 1,23,361,4907,62545,773171,9415897,113824139,1370909089,16481083619,
%T A025942 197954225833,2376538571771,28524991618033,342339076723667,
%U A025942 4108303998843769,49301058498065003,591621165177427777
%N A025942 Expansion of 1/((1-2x)(1-3x)(1-6x)(1-12x)).
%H A025942 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (23, -168, 468, -432).
%F A025942 a(0)=1, a(1)=23, a(2)=361, a(3)=4907, a(n)=23*a(n-1)-168*a(n-2)+ 468*a(n-3)- 432*a(n-4). - _Harvey P. Dale_, Oct 20 2012
%F A025942 a(n) = 16*12^n/5 -3*6^n -2^n/5 +3^n. - _R. J. Mathar_, Jun 04 2013
%t A025942 CoefficientList[Series[1/((1-2x)(1-3x)(1-6x)(1-12x)),{x,0,30}],x] (* or *) LinearRecurrence[{23,-168,468,-432},{1,23,361,4907},20] (* _Harvey P. Dale_, Oct 20 2012 *)
%o A025942 (PARI) Vec(1/((1-2*x)*(1-3*x)*(1-6*x)*(1-12*x))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012
%K A025942 nonn,easy
%O A025942 0,2
%A A025942 _N. J. A. Sloane_