A055074 -id:A055074 - cp's OEIS frontend

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

Patrick De Geest, Apr 15 2000

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

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

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

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

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

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

A055072 Primes in A054637.

Original entry on oeis.org

3, 5, 7, 11, 13, 19, 29, 31, 37, 41, 43, 47, 59, 61, 79, 83, 89, 97, 103, 109, 113, 127, 131, 137, 139, 151, 157, 163, 179, 181, 191, 193, 223, 227, 239, 241, 257, 263, 281, 283, 307, 311, 313, 331, 337, 347, 349, 353, 367, 373, 383, 397, 409, 419, 433, 439

Offset: 1

Patrick De Geest, Apr 15 2000

			012101112202122100101102110111112120121122200201...
--|..... sum 0+1+2 = prime 3
-----|.. sum 0+1+2+1+0+1 = prime 5
-------| sum 0+1+2+1+0+1+1+1 = prime 7

Cf. A054637, A055073, A055059-A055074.

Offset changed by Georg Fischer, Sep 02 2022

cp's OEIS Frontend

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

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