A291962 - OEIS

%I #18 Apr 01 2023 12:08:56

%S 0,1,1011,1101111,10001010111,10101101100111,11011001000000111,

%T 100001111010001000111,101010011000101011000111,

%U 110100111110110101111000111,1000010001110100011010111000111,1010010110010001100001100111000111,1100111011110101111010000000111000111

%N Decimal repunits written in base 2.

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

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

%H Seiichi Manyama, <a href="/A291962/b291962.txt">Table of n, a(n) for n = 0..301</a>

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

%t Table[FromDigits@ IntegerDigits[Floor[10^n/9], 2], {n, 0, 12}] (* _Michael De Vlieger_, Sep 06 2017 *)

%t FromDigits[IntegerDigits[#,2]]&/@Table[FromDigits[PadRight[{},n,1]],{n,0,20}] (* _Harvey P. Dale_, Apr 01 2023 *)

%o (PARI) a(n) = subst(Pol(binary((10^n-1)/9)), x, 10)

%o (Python)

%o def a(n): return 0 if n == 0 else int(bin(int("1"*n))[2:])

%o print([a(n) for n in range(13)]) # _Michael S. Branicky_, Apr 26 2022

%Y Cf. A000225, A002275, A007088, A088911.

%K nonn,base,easy

%O 0,3

%A _Felix Fröhlich_, Sep 06 2017