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A152775 Numbers with 3n binary digits where every run length is 3, written in binary. 4
111, 111000, 111000111, 111000111000, 111000111000111, 111000111000111000, 111000111000111000111, 111000111000111000111000, 111000111000111000111000111, 111000111000111000111000111000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
A152776 written in base 2.
LINKS
FORMULA
From Colin Barker, Apr 20 2014: (Start)
a(n) = (-1001-999*(-1)^n+2^(4+3*n)*125^(1+n))/18018.
a(n) = 1000*a(n-1)+a(n-2)-1000*a(n-3).
G.f.: 111*x / ((x-1)*(x+1)*(1000*x-1)). (End).
EXAMPLE
n ... a(n) .............. A152776(n)
1 ... 111 ............... 7
2 ... 111000 ............ 56
3 ... 111000111 ......... 455
4 ... 111000111000 ...... 3640
5 ... 111000111000111 ... 29127
MATHEMATICA
FromDigits/@Table[Flatten[PadRight[{}, n, {a, b}]/.{a->{1, 1, 1}, b->{0, 0, 0}}], {n, 10}] (* Harvey P. Dale, Mar 23 2012 *)
CoefficientList[Series[111/((x - 1) (x + 1) (1000 x - 1)), {x, 0, 20}], x] (* Vincenzo Librandi, Apr 21 2014 *)
PROG
(PARI) Vec(111*x / ((x-1)*(x+1)*(1000*x-1)) + O(x^100)) \\ Colin Barker, Apr 20 2014
CROSSREFS
Sequence in context: A145698 A362920 A244845 * A362118 A242646 A242645
KEYWORD
easy,nonn,base
AUTHOR
Omar E. Pol, Jan 18 2009
STATUS
approved

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Last modified March 5 09:07 EST 2024. Contains 370543 sequences. (Running on oeis4.)