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 A169585 #6 Apr 09 2025 15:12:37
%S A169585 1,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T A169585 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A169585 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A169585 A000004 preceded by 1, 3.
%C A169585 Inverse binomial transform of A016777; second inverse binomial transform of A053220; third inverse binomial transform of A027471 without first term; fourth inverse binomial transform of A081039.
%F A169585 a(0) = 1, a(1) = 3, a(n) = 0 for n > 1.
%F A169585 G.f.: 1+3*x.
%F A169585 a(n) = 3^n mod 9. - _Ridouane Oudra_, Apr 09 2025
%o A169585 (PARI) {concat([1, 3], vector(103))}
%Y A169585 Cf. A000004 (zero sequence), A016777 (3*n+1), A053220 ((3*n-1)*2^(n-2)), A027471 ((n-1)*3^(n-2)), A081039 ((3*n+4)*4^(n-1), a(0)=1, a(1)=7), A130706 (1, 2, 0, 0, 0, ...), A166926 (1, 2, 4, 0, 0, 0, ...), A130779 (1, 1, 2, 0, 0, 0, ...).
%K A169585 easy,nonn
%O A169585 0,2
%A A169585 _Klaus Brockhaus_, Dec 02 2009