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 A051063 #14 Mar 09 2022 16:31:43
%S A051063 9,18,36,45,63,72,90,99,117,126,144,153,171,180,198,207,225,234,252,
%T A051063 261,279,288,306,315,333,342,360,369,387,396,414,423,441,450,468,477,
%U A051063 495,504,522,531,549,558,576,585,603,612,630,639,657,666
%N A051063 27*n+9 or 27*n+18.
%D A051063 Letter from Gary W. Adamson concerning Prouhet-Thue-Morse sequence, Nov. 11, 1999.
%H A051063 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F A051063 a(n)=27*n-a(n-1) for n>0, a(0)=9. [_Vincenzo Librandi_, Aug 06 2010]
%F A051063 G.f. 9*x*( 1+x+x^2 ) / ( (1+x)*(x-1)^2 ). - _R. J. Mathar_, Sep 18 2013
%t A051063 LinearRecurrence[{1,1,-1},{9,18,36},60] (* _Harvey P. Dale_, Mar 09 2022 *)
%Y A051063 Equals 9*A001651(n).
%K A051063 nonn,easy
%O A051063 1,1
%A A051063 _N. J. A. Sloane_, _Gary W. Adamson_