A140429 a(n) = floor(3^(n-1)).

0, 1, 3, 9, 27, 81, 243, 729, 2187, 6561, 19683, 59049, 177147, 531441, 1594323, 4782969, 14348907, 43046721, 129140163, 387420489, 1162261467, 3486784401, 10460353203, 31381059609, 94143178827, 282429536481, 847288609443

Offset: 0

Author

Paul Curtz, Jun 19 2008

Keywords

• nonn
• easy

Comments

Binomial transform of Jacobsthal numbers A001045.

Implicit use in A094555 (Barry).

Links

• Index entries for linear recurrences with constant coefficients, signature (3).

Crossrefs

Cf. A000079, A131577, A133494.

Programs

PARI

a(n)=if(n<2,n,3^(n-1)) \\ Charles R Greathouse IV, Oct 03 2016

PARI

a(n)=floor(3^(n-1)) \\ M. F. Hasler, Apr 13 2018

Formula

a(n) = floor(3^(n-1)) = A000244(n-1) = A133494(n), n >= 1.

O.g.f.: x/(1-3x). - R. J. Mathar, Aug 27 2008

Extensions

Extended by R. J. Mathar, Aug 28 2008

New name by M. F. Hasler, Apr 13 2018