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A123760 Numbers whose binary expansion is 1xy100...0 where x,y = 0 or 1. 4
9, 11, 13, 15, 18, 22, 26, 30, 36, 44, 52, 60, 72, 88, 104, 120, 144, 176, 208, 240, 288, 352, 416, 480, 576, 704, 832, 960, 1152, 1408, 1664, 1920, 2304, 2816, 3328, 3840, 4608, 5632, 6656, 7680, 9216, 11264, 13312, 15360, 18432, 22528, 26624 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = 2*a(n-4) for n > 4.
A093873(a(n)) = 3.
Sum_{n>=1} 1/a(n) = 4448/6435. - Amiram Eldar, Mar 28 2022
MATHEMATICA
Union[Join @@ (Table[FromDigits[Join[#, Table[0, {n}]], 2], {n, 0, 11}] & /@ {{1, 0, 0, 1}, {1, 0, 1, 1}, {1, 1, 0, 1}, {1, 1, 1, 1}})] (* Amiram Eldar, Mar 28 2022 *)
CROSSREFS
Sequence in context: A248629 A008558 A335912 * A289686 A251394 A155877
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Oct 13 2006
STATUS
approved

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Last modified March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)