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%I #18 Apr 16 2018 11:10:20
%S 0,1,3,9,27,81,243,729,2187,6561,19683,59049,177147,531441,1594323,
%T 4782969,14348907,43046721,129140163,387420489,1162261467,3486784401,
%U 10460353203,31381059609,94143178827,282429536481,847288609443
%N a(n) = floor(3^(n-1)).
%C Binomial transform of Jacobsthal numbers A001045.
%C Implicit use in A094555 (Barry).
%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (3).
%F a(n) = floor(3^(n-1)) = A000244(n-1) = A133494(n), n >= 1.
%F O.g.f.: x/(1-3x). - _R. J. Mathar_, Aug 27 2008
%o (PARI) a(n)=if(n<2,n,3^(n-1)) \\ _Charles R Greathouse IV_, Oct 03 2016
%o (PARI) a(n)=floor(3^(n-1)) \\ _M. F. Hasler_, Apr 13 2018
%Y Cf. A000079, A131577, A133494.
%K nonn,easy
%O 0,3
%A _Paul Curtz_, Jun 19 2008
%E Extended by _R. J. Mathar_, Aug 28 2008
%E New name by _M. F. Hasler_, Apr 13 2018
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