A118586 Numbers whose binary expansion contains group of at least two 1's followed by a nonempty group of 0's.

6, 12, 14, 24, 28, 30, 48, 56, 60, 62, 96, 112, 120, 124, 126, 192, 224, 240, 248, 252, 254, 384, 448, 480, 496, 504, 508, 510, 768, 896, 960, 992, 1008, 1016, 1020, 1022, 1536, 1792, 1920, 1984, 2016, 2032, 2040, 2044, 2046, 3072, 3584, 3840, 3968, 4032

Offset

1,1

Comments

All terms are even.

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Formula

Sum_{n>=1} 1/a(n) = -1 + A065442. - Amiram Eldar, Feb 20 2022

Example

4080_10 = 111111110000_2.

Mathematica

Sort[Flatten[Table[Sum[2^k, {k, k1, k2}], {k1, 1, 10}, {k2, k1+1, 11}]]]

Prog

(Python)
from itertools import count, islice
def agen(): # generator of terms
    for d in count(3):
        for i in range(2, d):
            yield int("1"*i + "0"*(d-i), 2)
print(list(islice(agen(), 50))) # Michael S. Branicky, Feb 20 2022

Crossrefs

Cf. A043569, A065442.

Sequence in context: A214399 A079946 A315614 * A293907 A259397 A183029

Adjacent sequences: A118583 A118584 A118585 * A118587 A118588 A118589

Keyword

base,nonn

Author

Zak Seidov, May 07 2006

Status

approved