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A004781 Binary expansion contains 3 adjacent 1's. 5
7, 14, 15, 23, 28, 29, 30, 31, 39, 46, 47, 55, 56, 57, 58, 59, 60, 61, 62, 63, 71, 78, 79, 87, 92, 93, 94, 95, 103, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 135, 142, 143, 151, 156, 157, 158, 159, 167 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for 2-automatic sequences.

FORMULA

a(n) ~ n. - Charles R Greathouse IV, Sep 24 2012

MATHEMATICA

Select[Range[200], MemberQ[Partition[IntegerDigits[#, 2], 3, 1], {1, 1, 1}]&]  (* Harvey P. Dale, Mar 31 2011 *)

PROG

(Haskell)

a004781 n = a004781_list !! (n - 1)

a004781_list = filter f [0..] where

   f x | x < 7     = False

       | otherwise = (x `mod` 8) == 7 || f (x `div` 2)

-- Reinhard Zumkeller, Jun 03 2012

(PARI) is(n)=!!bitand(bitand(n, n<<1), n<<2) \\ Charles R Greathouse IV, Sep 24 2012

CROSSREFS

Complement of A003726.

Cf. A004779, A136037.

Sequence in context: A085335 A069137 A141164 * A004759 A062056 A173024

Adjacent sequences:  A004778 A004779 A004780 * A004782 A004783 A004784

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Offset corrected by Reinhard Zumkeller, Jun 03 2012

STATUS

approved

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Last modified March 18 19:58 EDT 2019. Contains 321293 sequences. (Running on oeis4.)