A291962 Decimal repunits written in base 2.

0, 1, 1011, 1101111, 10001010111, 10101101100111, 11011001000000111, 100001111010001000111, 101010011000101011000111, 110100111110110101111000111, 1000010001110100011010111000111, 1010010110010001100001100111000111, 1100111011110101111010000000111000111

Offset

0,3

Comments

Interpreting A002275 as binary numbers and converting to decimal gives A000225. This sequence gives the resulting terms of the "reverse" operation.

The n least significant bits of a(n) seem to converge to A088911 as n increases.

Links

Seiichi Manyama, Table of n, a(n) for n = 0..301

Formula

a(n) = A007088(A002275(n)).

Mathematica

Table[FromDigits@ IntegerDigits[Floor[10^n/9], 2], {n, 0, 12}] (* Michael De Vlieger, Sep 06 2017 *)
FromDigits[IntegerDigits[#, 2]]&/@Table[FromDigits[PadRight[{}, n, 1]], {n, 0, 20}] (* Harvey P. Dale, Apr 01 2023 *)

Prog

(PARI) a(n) = subst(Pol(binary((10^n-1)/9)), x, 10)
(Python)
def a(n): return 0 if n == 0 else int(bin(int("1"*n))[2:])
print([a(n) for n in range(13)]) # Michael S. Branicky, Apr 26 2022

Crossrefs

Cf. A000225, A002275, A007088, A088911.

Sequence in context: A267613 A178396 A178349 * A094946 A158877 A159774

Adjacent sequences: A291959 A291960 A291961 * A291963 A291964 A291965

Keyword

nonn,base,easy

Author

Felix Fröhlich, Sep 06 2017

Status

approved