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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.

A308705 Decimal expansion of the constant formed by concatenating the terms of A076478 (binary vectors of lengths 1, 2, 3, ... in numerical order).

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%I A308705 #18 May 13 2021 01:44:40
%S A308705 2,7,6,3,8,7,1,1,7,2,7,9,4,8,6,5,2,3,7,3,4,1,9,8,6,7,6,2,1,1,9,0,1,2,
%T A308705 3,0,5,5,5,0,8,9,9,8,8,1,6,0,6,8,5,5,0,6,1,4,3,6,7,6,8,1,9,1,1,5
%N A308705 Decimal expansion of the constant formed by concatenating the terms of A076478 (binary vectors of lengths 1, 2, 3, ... in numerical order).
%C A308705 The binary vectors "0,1,00,01,10,11,000,001,..." are concatenated into a constant "0.0100011011000001...", then converted to decimal.
%e A308705 0.276387117279486523734198676211901230555089988160685506143676819115...
%t A308705 m = 100; d[n_] := Rest@IntegerDigits[n + 1, 2] + 1; v = Flatten[Array[d, 4 m]] - 1; RealDigits[FromDigits[v, 2]/2^Length[v], 10, m][[1]] (* _Amiram Eldar_, Jul 05 2019 after _Clark Kimberling_ at A076478 *)
%o A308705 (Python)
%o A308705 from bigfloat import *
%o A308705 import string
%o A308705 def GenerateBitstring(bitstring, suffix, recurse):
%o A308705     if recurse == 0:
%o A308705         bitstring = bitstring + suffix
%o A308705     else:
%o A308705         bitstring = GenerateBitstring(bitstring, suffix + "0", recurse-1)
%o A308705         bitstring = GenerateBitstring(bitstring, suffix + "1", recurse-1)
%o A308705     return bitstring
%o A308705 VulcanBinary = ""
%o A308705 MaxRecursion = 8
%o A308705 for i in range(1,MaxRecursion+1):
%o A308705     VulcanBinary = GenerateBitstring(VulcanBinary, "", i)
%o A308705 print('.' + VulcanBinary)
%o A308705 with precision(2000):
%o A308705     VulcanDecimal = BigFloat(0)
%o A308705     b = BigFloat(1)
%o A308705     for c in VulcanBinary:
%o A308705         b = b/2.
%o A308705         if c == '1':
%o A308705             VulcanDecimal = VulcanDecimal+b
%o A308705 print(VulcanDecimal)
%o A308705 print(string.join(x + ',' for x in str(VulcanDecimal)[2:]))
%Y A308705 Cf. A076478.
%K A308705 nonn,base,cons
%O A308705 0,1
%A A308705 _David McFadzean_, Jun 18 2019