A055143 The first n digits of the juxtaposition of the base-2 numbers converted to decimal.

1, 3, 6, 13, 27, 55, 110, 220, 441, 882, 1765, 3531, 7063, 14126, 28253, 56507, 113015, 226031, 452062, 904124, 1808248, 3616497, 7232994, 14465988, 28931977, 57863955, 115727910, 231455821, 462911642, 925823285, 1851646570, 3703293141, 7406586283, 14813172567

Offset

1,2

Links

Michael S. Branicky, Table of n, a(n) for n = 1..3322

Example

1 (1); 11 (3); 110 (6); 1101 (13); 11011 (27); 110111 (55); ...

Mathematica

With[{c=Flatten[Table[IntegerDigits[n, 2], {n, 20}]]}, Table[FromDigits[ Take[ c, k], 2], {k, Length[c]}]] (* Harvey P. Dale, May 15 2021 *)

Prog

(Python)
from itertools import count, islice
def agen():
    k, chap = 1, "1"
    for n in count(1):
        while len(chap) < n: k += 1; chap += bin(k)[2:]
        yield int(chap[:n], 2)
print(list(islice(agen(), 34))) # Michael S. Branicky, Oct 06 2022

Crossrefs

Cf. A030190, A054633, A055074, A055144-A055150.

Sequence in context: A033129 A079403 A065830 * A092539 A094386 A371902

Adjacent sequences: A055140 A055141 A055142 * A055144 A055145 A055146

Keyword

nonn,base

Author

Patrick De Geest, Apr 15 2000

Extensions

a(32) and beyond from Michael S. Branicky, Oct 06 2022

Status

approved