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 A116555 #14 Dec 17 2022 06:35:23
%S A116555 1,9,10,81,91,90,109,729,820,819,991,810,991,981,1180,6561,7399,7380,
%T A116555 8929,7371,9010,8919,10729,7290,9091,8919,10720,8829,10801,10620,
%U A116555 12781,59049,66790,66591,80551,66420,81199,80361,96670,66339,82639,81090
%N A116555 a(2*n+1) = 9*a(n), a(2*n+2) = 10*a(n) + a(n-1).
%H A116555 G. C. Greubel, <a href="/A116555/b116555.txt">Table of n, a(n) for n = 0..2500</a>
%F A116555 From _G. C. Greubel_, Oct 30 2016: (Start)
%F A116555 a(2*n+1) = 9*a(n).
%F A116555 a(2*n+2) = 10*a(n) + a(n-1). (End)
%t A116555 b[0] := 0; b[1] := 1;
%t A116555 b[n_?EvenQ] := b[n] = 9*b[n/2];
%t A116555 b[n_?OddQ] := b[n] = 10*b[(n - 1)/2] + b[(n - 3)/2];
%t A116555 Table[b[n], {n, 1, 70}]
%Y A116555 Cf. A116528, A116529, A116552, A116553, A116554.
%K A116555 nonn,easy
%O A116555 0,2
%A A116555 _Roger L. Bagula_, Mar 15 2006
%E A116555 New name using formula, _Joerg Arndt_, Dec 17 2022