|
| |
| |
|
|
|
1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4, 1, 2, 4
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Periodic sequence with period [1,2,4] . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Sep 25 2006
a(n) = cubefree part of 2^n (n=0,1,2,3,...) [From Artur Jasinski (grafix(AT)csl.pl), Oct 15 2008]
Contribution from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 23 2010: (Start)
Continued fraction expansion of (11+sqrt(229))/18.
Decimal expansion of 124/999. (End)
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (0,0,1).
|
|
|
FORMULA
| n=0 mod 3 -> a(n)=1 n=1 mod 3 -> a(n)=2 n=2 mod 3 -> a(n)=4
a(n)=2^mod(n, 3) - Paul Barry (pbarry(AT)wit.ie), Oct 06 2003
a(n)=1/9*{16*(n mod 3)+[(n+1) mod 3]+4*[(n+2) mod 3]} - Paolo P. Lava (paoloplava(AT)gmail.com), Nov 21 2006
a(n) = a(n-3). G.f.: (1+2*x+4*x^2)/((1-x) * (1+x+x^2)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 13 2010]
|
|
|
EXAMPLE
| a(4)=16 mod 7=2, a(5)=32 mod 7=4, a(6)=64 mod 7=1
|
|
|
MAPLE
| A069705 := proc(n) op((n mod 3)+1, [1, 2, 4]) ; end proc: # R. J. Mathar, Feb 05 2011
|
|
|
MATHEMATICA
| CubefreePart[n_Integer?Positive] := Times @@ Power @@@ ({#[[1]], Mod[ #[[2]], 3]} & /@ FactorInteger[n]); Table[CubefreePart[2^n], {n, 0, 400}] [From Artur Jasinski (grafix(AT)csl.pl), Oct 15 2008]
|
|
|
PROG
| (Other) sage: [power_mod(2, n, 7)for n in xrange(0, 105)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 07 2009]
(MAGMA) [ 2^n mod 7: n in [0..65]]; // From Vincenzo Librandi, Feb 05 2011
|
|
|
CROSSREFS
| A145642 [From Artur Jasinski (grafix(AT)csl.pl), Oct 15 2008]
Cf. A178233 (decimal expansion of (11+sqrt(229))/18). [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 23 2010]
Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 01 2010: (Start)
Appears in A179132.
(End)
Sequence in context: A206475 A124911 A132954 * A106645 A115314 A062039
Adjacent sequences: A069702 A069703 A069704 * A069706 A069707 A069708
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Jon Perry (perry(AT)globalnet.co.uk), Jan 14 2003
|
| |
|
|
