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A033128
Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,0,1.
2
1, 10, 101, 1011, 10110, 101101, 1011011, 10110110, 101101101, 1011011011, 10110110110, 101101101101, 1011011011011, 10110110110110, 101101101101101, 1011011011011011, 10110110110110110, 101101101101101101, 1011011011011011011, 10110110110110110110
OFFSET
1,2
FORMULA
a(n) = 10*a(n-1) +a(n-3) -10*a(n-4). G.f.: x*(1+x^2)/((x-1) * (10*x-1) * (1+x+x^2)). - R. J. Mathar, Oct 05 2009
a(n) = floor((101/999)*10^n). - Tani Akinari, Jul 22 2015
MATHEMATICA
nn=20; With[{c=PadRight[{}, nn, {1, 0, 1}]}, Table[FromDigits[ Take[ c, n]], {n, nn}]] (* Harvey P. Dale, Dec 30 2012 *)
CROSSREFS
Sequence in context: A284179 A096883 A266720 * A094945 A190480 A267623
KEYWORD
nonn,base
EXTENSIONS
More terms from Harvey P. Dale, Dec 30 2012
STATUS
approved