cp's OEIS Frontend

A171171 Corner sequence (starting each round with the corner (SE): 1,2,3).

%I A171171 #6 Feb 24 2021 02:48:19
%S A171171 1,2,3,4,1,2,3,2,3,4,3,4,1,4,1,2,1,2,3,2,3,4,3,4,1,4,1,2,1,2,3,2,3,4,
%T A171171 1,2,3,2,3,4,3,4,1,2,3,4,3,4,1,4,1,2,3,4,1,4,1,2,1,2,3,4,1,2,1,2,3,2,
%U A171171 3,4,3,4,1,4,1,2,1,2,3,2,3,4,1,2,3,2,3,4,3,4,1,2,3,4,3,4,1,4,1,2,3,4,1,4,1
%N A171171 Corner sequence (starting each round with the corner (SE): 1,2,3).
%C A171171 See A161411, which is the main entry for this sequence.
%C A171171 See also A171170 for another version.
%H A171171 David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]
%H A171171 N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a>
%e A171171 ================
%e A171171 .......41.......
%e A171171 .......32.......
%e A171171 ================
%e A171171 ......4141......
%e A171171 ......3..2......
%e A171171 ......4..1......
%e A171171 ......3232......
%e A171171 ================
%e A171171 .....41..41.....
%e A171171 .....3....2.....
%e A171171 ................
%e A171171 ................
%e A171171 .....4....1.....
%e A171171 .....32..32.....
%e A171171 ================
%e A171171 ....41414141....
%e A171171 ....3..23..2....
%e A171171 ....4......1....
%e A171171 ....32....32....
%e A171171 ....41....41....
%e A171171 ....3......2....
%e A171171 ....4..14..1....
%e A171171 ....32323232....
%e A171171 ================
%e A171171 ...41......41...
%e A171171 ...3........2...
%e A171171 ................
%e A171171 ................
%e A171171 ................
%e A171171 ................
%e A171171 ................
%e A171171 ................
%e A171171 ................
%e A171171 ...4........1...
%e A171171 ...32......32...
%e A171171 ================
%e A171171 And so on.
%e A171171 Triangle begins:
%e A171171 1,2,3,4;
%e A171171 1,2,3, 2,3,4, 3,4,1, 4,1,2;
%e A171171 1,2,3, 2,3,4, 3,4,1, 4,1,2;
%e A171171 1,2,3,2,3,4,1,2,3, 2,3,4,3,4,1,2,3,4, 3,4,1,4,1,2,3,4,1, 4,1,2,1,2,3,4,1,2;
%e A171171 1,2,3, 2,3,4, 3,4,1, 4,1,2;
%e A171171 1,2,3,2,3,4,1,2,3, 2,3,4,3,4,1,2,3,4, 3,4,1,4,1,2,3,4,1, 4,1,2,1,2,3,4,1,2;
%e A171171 Contribution from _Omar E. Pol_, Dec 09 2009: (Start)
%e A171171 Illustration for n = 1..148
%e A171171 ================
%e A171171 .41..41..41..41.
%e A171171 .341412..341412.
%e A171171 ..3412....3412..
%e A171171 ..434141414121..
%e A171171 .43234123412321.
%e A171171 .32.43414121.32.
%e A171171 ....32341232....
%e A171171 ....41432141....
%e A171171 .41.34323212.41.
%e A171171 .34143214321412.
%e A171171 ..343232323212..
%e A171171 ..4321....4321..
%e A171171 .432321..432321.
%e A171171 .32..32..32..32.
%e A171171 ================
%e A171171 (End)
%Y A171171 Cf. A139250, A139251, A160410, A161411, A171170.
%K A171171 nonn,tabf
%O A171171 1,2
%A A171171 _Omar E. Pol_, Dec 04 2009