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A105398
A simple "Fractal Jump Sequence" (FJS).
7
4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4, 8, 4
OFFSET
4,1
COMMENTS
See A105397 for definition of Fractal Jump Sequence.
Continued fraction expansion of (4+3*sqrt(2))/2. - Bruno Berselli, Nov 09 2011
Period 2: repeat [4, 8]. - Wesley Ivan Hurt, Feb 12 2017
FORMULA
G.f.: -4*x^4*(1+2*x) / ( (x-1)*(1+x) ). - R. J. Mathar, Jul 07 2011
a(n) = a(-n) = a(n-2) = 2*(3-(-1)^n) = 2^((5-(-1)^n)/2). - Bruno Berselli, Nov 09 2011
MAPLE
A105398:=n->2*(3-(-1)^n): seq(A105398(n), n=0..150); # Wesley Ivan Hurt, Feb 12 2017
MATHEMATICA
PadRight[{}, 110, {4, 8}] (* Harvey P. Dale, Nov 09 2011 *)
PROG
(Sage) [power_mod(2, n, 12)for n in range(2, 108)] # Zerinvary Lajos, Nov 03 2009
(Maxima) makelist(if evenp(n) then 4 else 8, n, 0, 30); /* Martin Ettl, Nov 12 2012 */
CROSSREFS
Cf. A105397.
Sequence in context: A155970 A348573 A010713 * A005883 A055026 A336818
KEYWORD
nonn,base,easy
AUTHOR
Eric Angelini, May 01 2005
STATUS
approved