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

Author

Patrick De Geest, Apr 15 2000

Keywords

• nonn
• base

Examples

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

Links

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

Crossrefs

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

Programs

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 *)

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

Extensions

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