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A010724
Period 2: repeat (6,8).
3
6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6
OFFSET
0,1
COMMENTS
Decimal expansion of 68/99. - David A. Corneth, Oct 18 2016
FORMULA
a(n) = (-1)^(n+1)+7. - Paolo P. Lava, Oct 27 2006
G.f.: ( -6-8*x ) / ((x-1)*(1+x)). - R. J. Mathar, Nov 21 2011
a(0)=6, a(n) = 10 - eulerphi(a(n-1)) for n>0. - Alexander R. Povolotsky, Oct 16 2016
MATHEMATICA
NestList[10 - EulerPhi@ # &, 6, 120] (* or *)
CoefficientList[Series[(-6 - 8 x)/((x - 1) (1 + x)), {x, 0, 120}], x] (* Michael De Vlieger, Oct 21 2016 *)
PROG
(PARI) a(n)=6+n%2*2 \\ Charles R Greathouse IV, Dec 08 2015
CROSSREFS
Cf. A176401.
Sequence in context: A088751 A153627 A094540 * A196822 A065356 A019797
KEYWORD
nonn,easy
AUTHOR
STATUS
approved