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A154807
Numbers with 5n binary digits where every run length is 5, written in binary.
3
11111, 1111100000, 111110000011111, 11111000001111100000, 1111100000111110000011111, 111110000011111000001111100000, 11111000001111100000111110000011111, 1111100000111110000011111000001111100000, 111110000011111000001111100000111110000011111
OFFSET
1,1
COMMENTS
A154808 written in base 2.
FORMULA
From Colin Barker, Apr 20 2014: (Start)
a(n) = (-100001-99999*(-1)^n+2^(6+5*n)*3125^(1+n))/1800018.
a(n) = 100000*a(n-1)+a(n-2)-100000*a(n-3).
G.f.: 11111*x / ((x-1)*(x+1)*(100000*x-1)). (End)
EXAMPLE
n ... a(n) ........................ A154808(n)
1 ... 11111 ....................... 31
2 ... 1111100000 .................. 992
3 ... 111110000011111 ............. 31775
4 ... 11111000001111100000 ........ 1016800
5 ... 1111100000111110000011111 ... 32537631
MATHEMATICA
CoefficientList[Series[11111/((x - 1) (x + 1) (100000 x - 1)), {x, 0, 10}], x] (* Vincenzo Librandi, Apr 22 2014 *)
LinearRecurrence[{100000, 1, -100000}, {11111, 1111100000, 111110000011111}, 20] (* Harvey P. Dale, Aug 08 2023 *)
PROG
(PARI) Vec(11111*x/((x-1)*(x+1)*(100000*x-1)) + O(x^100)) \\ Colin Barker, Apr 20 2014
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Omar E. Pol, Jan 25 2009
EXTENSIONS
More terms from Colin Barker, Apr 20 2014
STATUS
approved