login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A064235 The smallest power of 3 that is greater than or equal to n. 4
1, 3, 3, 9, 9, 9, 9, 9, 9, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Let A_n be the upper triangular matrix in the group GL(n,3) of invertible n X n matrices over GF(3) that has zero entries below the diagonal and 1 elsewhere. For example for n=4 the matrix is / 1,1,1,1 / 0,1,1,1 / 0,0,1,1 / 0,0,0,1 /. a(n) is the order of this matrix as an element of GL(n,3).

For n>1 a(n) is the smallest integer such that gcd(a(n),2^a(n)+1) >= n. - Benoit Cloitre, Apr 21 2002

a(n) = 3 ^ A080342(n). - Reinhard Zumkeller, Sep 02 2015

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MAPLE

A064235 := proc(n)

        ceil(log(n)/log(3)) ;

        3^% ;

end proc: # R. J. Mathar, Nov 06 2011

MATHEMATICA

nn=100; With[{p3=3^Range[0, Ceiling[Log[3, nn]]]}, Flatten[Table[Select[ p3, #>=n&, 1], {n, nn}]]] (* Harvey P. Dale, Mar 14 2013 *)

PROG

(Haskell)

import Data.List (transpose)

a064235 n = genericIndex a064235_list (n - 1)

a064235_list = 1 : zs where

   zs = 3 : 3 : (map (* 3) $ concat $ transpose [zs, zs, zs])

-- Reinhard Zumkeller, Sep 02 2015

CROSSREFS

Cf. A062383.

Cf. A132171, A080342, A000244.

Sequence in context: A155686 A290300 A201456 * A098355 A183429 A107443

Adjacent sequences:  A064232 A064233 A064234 * A064236 A064237 A064238

KEYWORD

nonn

AUTHOR

Dan Fux (dan.fux(AT)OpenGaia.com or danfux(AT)OpenGaia.com), Sep 22 2001

EXTENSIONS

More terms from James A. Sellers, Sep 26 2001

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 14 23:27 EST 2018. Contains 317221 sequences. (Running on oeis4.)