cp's OEIS Frontend

A291802 Take n-th word over {1,2} listed in A291797 and apply the Post tag system described in A284116 (but adapted to the alphabet {1,2}); a(n) = position of the longest word in the orbit, or -1 if the orbit is unbounded.

%I A291802 #9 Sep 08 2017 16:13:56
%S A291802 0,3,0,0,16,14,0,0,0,13,15,11,23,9,0,18,0,22,20,0,12,8,24,10,20,18,2,
%T A291802 6,106,16,0,23,27,0,0,0,27,5,25,0,0,105,3,103,37,15,1,1,107,17,19,101,
%U A291802 9,99,2,35,7,7,31,13,71,97,0,0,0,0,0,22,0,34,0,0,0
%N A291802 Take n-th word over {1,2} listed in A291797 and apply the Post tag system described in A284116 (but adapted to the alphabet {1,2}); a(n) = position of the longest word in the orbit, or -1 if the orbit is unbounded.
%C A291802 Post's tag system maps a word w over {1,2} to w', where if w begins with 1, w' is obtained by appending 11 to w and deleting the first three letters, or if w begins with 2, w' is obtained by appending 2212 to w and deleting the first three letters.
%C A291802 We work over {1,2} rather than the official alphabet {0,1} because of the prohibition in the OEIS of terms (other than 0 itself) which begin with 0.
%C A291802 This is an analog of A291796 for the words in A291797.
%H A291802 Lars Blomberg, <a href="/A291802/b291802.txt">Table of n, a(n) for n = 1..8190</a> (For terms in A291797 up to length 36.)
%H A291802 Peter R. J. Asveld, <a href="http://doc.utwente.nl/66184/1/1988m20.pdf">On a Post's System of Tag</a>. Bulletin of the EATCS 36 (1988), 96-102. See Table 3.
%Y A291802 Cf. A284116, A291794, A291795, A291796, A291797.
%K A291802 nonn
%O A291802 1,2
%A A291802 _N. J. A. Sloane_, Sep 04 2017
%E A291802 a(31)-a(73) from _Lars Blomberg_, Sep 08 2017