cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

This page as a plain text file.
%I A355328 #26 Jul 07 2022 02:01:00
%S A355328 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,
%T A355328 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,
%U A355328 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
%N A355328 Decimal expansion of the number whose binary expansion differs from its decimal expansion only in the first digit.
%C A355328 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.
%C A355328 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)...
%e A355328 0.100110011010000011001111010001110100101001000111010001001101001011...
%t A355328 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 *)
%Y A355328 Cf. A352677 (golden base = binary).
%K A355328 nonn,cons
%O A355328 0,1
%A A355328 _Leonid Broukhis_, Jun 29 2022