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 A016247 #21 Jul 08 2025 05:44:18
%S A016247 1,18,241,2910,33565,378546,4219993,46755846,516329845,5691721530,
%T A016247 62681496241,689931815118,7591862105101,83526155988930,
%U A016247 918881752875145,10108263503608086,111194283871577893,1223157434578690506,13454853652313597665,148004121407137586910,1628049722868641531581
%N A016247 Expansion of 1/((1-x) * (1-6*x) * (1-11*x)).
%H A016247 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (18, -83, 66).
%F A016247 a(0)=1, a(1)=18, a(n)=17*a(n-1)-66*a(n-2)+1. - _Vincenzo Librandi_, Feb 10 2011
%F A016247 a(0)=1, a(1)=18, a(2)=241, a(n)=18*a(n-1)-83*a(n-2)+66*a(n-3). - _Harvey P. Dale_, Sep 23 2012
%F A016247 a(n) = (11^(n+2) - 2*6^(n+2) + 1)/50. [_Yahia Kahloune_, Aug 13 2013]
%F A016247 From _Seiichi Manyama_, May 05 2025: (Start)
%F A016247 a(n) = Sum_{k=0..n} 5^k * binomial(n+2,k+2) * Stirling2(k+2,2).
%F A016247 a(n) = Sum_{k=0..n} (-5)^k * 11^(n-k) * binomial(n+2,k+2) * Stirling2(k+2,2). (End)
%t A016247 CoefficientList[Series[1/((1-x)(1-6x)(1-11x)),{x,0,30}],x] (* or *) LinearRecurrence[{18,-83,66},{1,18,241},30] (* _Harvey P. Dale_, Sep 23 2012 *)
%o A016247 (PARI) a(n) = (11^(n+2) - 2*6^(n+2) + 1)/50; \\ _Joerg Arndt_, Aug 13 2013
%Y A016247 Cf. A016209, A016223, A016234.
%K A016247 nonn
%O A016247 0,2
%A A016247 _N. J. A. Sloane_