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 A196666 #29 Mar 25 2025 19:45:37
%S A196666 1,15,330,7260,159720,3513840,77304480,1700698560,37415368320,
%T A196666 823138103040,18109038266880,398398841871360,8764774521169920,
%U A196666 192825039465738240,4242150868246241280,93327319101417308160,2053201020231180779520,45170422445085977149440
%N A196666 Expansion of g.f. (1 - 7*x)/(1 - 22*x).
%H A196666 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (22).
%F A196666 a(0) = 1, a(n) = 15*22^(n-1) for n>0.
%F A196666 a(n) = Sum_{k=0..n} A193722(n,k)*7^k.
%F A196666 From _Elmo R. Oliveira_, Mar 25 2025: (Start)
%F A196666 E.g.f.: (15*exp(22*x) + 7)/22.
%F A196666 a(n) = 22*a(n-1) for n > 1. (End)
%o A196666 (PARI) a(n)=if(n,15*22^n--,1) \\ _Charles R Greathouse IV_, Oct 06 2011
%Y A196666 Cf. A002001, A193722, A196661, A196662, A196663, A196664, A196665.
%K A196666 nonn,easy
%O A196666 0,2
%A A196666 _Philippe Deléham_, Oct 05 2011