A190619 Binary expansions of odd numbers with a single zero in their binary expansion.

101, 1011, 1101, 10111, 11011, 11101, 101111, 110111, 111011, 111101, 1011111, 1101111, 1110111, 1111011, 1111101, 10111111, 11011111, 11101111, 11110111, 11111011, 11111101, 101111111, 110111111, 111011111, 111101111, 111110111, 111111011, 111111101, 1011111111, 1101111111, 1110111111, 1111011111, 1111101111, 1111110111, 1111111011, 1111111101

Offset

1,1

Comments

a(n) = A007088(A190620(n)). [Reinhard Zumkeller, May 14 2011]

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Maple

f:=k->(10^k-1)/9; for n from 3 to 12 do for i from n-2 by -1 to 1 do j:=f(n)-10^i; lprint(j); od; od;

Prog

(Haskell)
a190619 n = a190619_list !! (n-1)
a190619_list = map read $ f 2 1 :: [Integer] where
  f m k
    | k < m - 1 = ((take k ones) ++ "0" ++ (take (m-k) ones)) : f m (k+1)
    | otherwise = ((take k ones) ++ "01") : f (m + 1) 1
  ones = repeat '1'
-- Reinhard Zumkeller, May 15 2011
(Python)
from itertools import count, islice
def agen():
    for d in count(3):
        b = (10**d - 1)//9
        for i in range(2, d):
            yield b - 10**(d-i)
print(list(islice(agen(), 50))) # Michael S. Branicky, Oct 13 2022

Crossrefs

Sequence in context: A290193 A289462 A289578 * A290197 A171823 A289528

Adjacent sequences: A190616 A190617 A190618 * A190620 A190621 A190622

Keyword

nonn,base

Author

N. J. A. Sloane, May 14 2011

Status

approved