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%I #13 Jan 24 2024 23:49:16
%S 1,3,7,9,15,17,19,21,31,33,35,37,39,41,43,45,63,65,67,69,71,73,75,77,
%T 79,81,83,85,87,89,91,93,127,129,131,133,135,137,139,141,143,145,147,
%U 149,151,153,155,157,159,161,163,165,167,169,171,173,175,177,179
%N Positions of words in A076478 that start with 0 and end with 0.
%C The sequences A346303, A171757, A346304, A346305 partition the positive integers. See A076478 for a guide to related sequences.
%C The position of the words 0, 00, 000, 0000, ... (all-zero) in A076478 is given by A000225. So this sequence is given by the subsequence A000225 and filling the gaps halfway up (until the leading 0 toggles) with odd numbers, from 7 to 9, from 15 to 21, from 31 to 45 etc. So the first differences are 2, 4, 2, 6, 2, 2, 2, 10, 2, 2, 2, 2, 2, 2, 2, 18, 2, 2, ... which is A052548 with 1, 3, 7, 15,... (A000225) intermediate 2's. - _R. J. Mathar_, Sep 08 2021
%e The first fourteen words w(n) are 0, 1, 00, 01, 10, 11, 000, 001, 010, 011, 100, 101, 110, 111, so that a(3) = 7.
%t (See A007931.)
%Y Cf. A007931, A076478, A171757, A346304, A346305.
%K nonn,base
%O 1,2
%A _Clark Kimberling_, Jul 21 2021