A355328 Decimal expansion of the number whose binary expansion differs from its decimal expansion only in the first digit.

1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1

Offset: 0

Author

Leonid Broukhis, Jun 29 2022

Keywords

• nonn
• cons

Comments

The decimal fraction 0.1 has binary expansion starting with 0.0001...; copying the suffix 001 (3 digits, as 3 < log_2(10) < 4) we obtain 0.1001, which expands to 0.00011001101, etc.

Alternatively the process can be described as greedily expressing 1/2 with digits of weights 1/2^n-1/10^n. With f(n)=1/2^n-1/10^n, 0.5 = f(1)+f(4)+f(5)+f(8)+f(9)+f(11)...

Examples

			0.100110011010000011001111010001110100101001000111010001001101001011...
		

Crossrefs

Cf. A352677 (golden base = binary).

Programs

Mathematica

seq[len_] := Module[{s = Table[0, {len}], x = 1/10, n = 1, c = 0}, s[[1]] = 1; While[n < len, While[1/2^n - 1/10^n > x, n++]; c++; s[[n]] = 1; x -= (1/2^n - 1/10^n)]; s]; seq[100] (* Amiram Eldar, Jun 29 2022 *)