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 A196665 #16 Mar 24 2025 22:33:27
%S A196665 1,13,247,4693,89167,1694173,32189287,611596453,11620332607,
%T A196665 220786319533,4194940071127,79703861351413,1514373365676847,
%U A196665 28773093947860093,546688785009341767,10387086915177493573,197354651388372377887,3749738376379075179853
%N A196665 Expansion of g.f. (1-6*x)/(1-19*x).
%H A196665 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (19).
%F A196665 a(0) = 1, a(n) = 13*19^(n-1) for n>0.
%F A196665 a(n) = Sum_{k=0..n} A193722(n,k)*6^k.
%F A196665 From _Elmo R. Oliveira_, Mar 18 2025: (Start)
%F A196665 E.g.f.: (13*exp(19*x) + 6)/19.
%F A196665 a(n) = 19*a(n-1) for n > 1. (End)
%Y A196665 Cf. A002001, A193722, A196661, A196662, A196663, A196664.
%K A196665 nonn,easy
%O A196665 0,2
%A A196665 _Philippe Deléham_, Oct 05 2011