cp's OEIS Frontend

A171170 Corner sequence (starting each round in the first quadrant).

%I A171170 #6 Feb 24 2021 02:48:19
%S A171170 1,2,3,4,4,1,2,1,2,3,2,3,4,3,4,1,4,1,2,1,2,3,2,3,4,3,4,1,3,4,1,4,1,2,
%T A171170 1,2,3,4,1,2,1,2,3,2,3,4,1,2,3,2,3,4,3,4,1,2,3,4,3,4,1,4,1,2,4,1,2,1,
%U A171170 2,3,2,3,4,3,4,1,3,4,1,4,1,2,1,2,3,4,1,2,1,2,3,2,3,4,1,2,3,2,3,4,3,4,1,2,3
%N A171170 Corner sequence (starting each round in the first quadrant).
%C A171170 See A161411, which is the main entry for this sequence.
%C A171170 See also A171171 for another version.
%H A171170 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 A171170 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 A171170 ================
%e A171170 .......41.......
%e A171170 .......32.......
%e A171170 ================
%e A171170 ......4141......
%e A171170 ......3..2......
%e A171170 ......4..1......
%e A171170 ......3232......
%e A171170 ================
%e A171170 .....41..41.....
%e A171170 .....3....2.....
%e A171170 ................
%e A171170 ................
%e A171170 .....4....1.....
%e A171170 .....32..32.....
%e A171170 ================
%e A171170 ....41414141....
%e A171170 ....3..23..2....
%e A171170 ....4......1....
%e A171170 ....32....32....
%e A171170 ....41....41....
%e A171170 ....3......2....
%e A171170 ....4..14..1....
%e A171170 ....32323232....
%e A171170 ================
%e A171170 ...41......41...
%e A171170 ...3........2...
%e A171170 ................
%e A171170 ................
%e A171170 ................
%e A171170 ................
%e A171170 ................
%e A171170 ................
%e A171170 ................
%e A171170 ...4........1...
%e A171170 ...32......32...
%e A171170 ================
%e A171170 And so on.
%e A171170 Triangle begins:
%e A171170 1,2,3,4;
%e A171170 4,1,2, 1,2,3, 2,3,4, 3,4,1;
%e A171170 4,1,2, 1,2,3, 2,3,4, 3,4,1;
%e A171170 3,4,1,4,1,2,1,2,3, 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;
%e A171170 4,1,2, 1,2,3, 2,3,4, 3,4,1;
%e A171170 3,4,1,4,1,2,1,2,3, 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;
%e A171170 Contribution from _Omar E. Pol_, Dec 09 2009: (Start)
%e A171170 Illustration for n = 1..148
%e A171170 ================
%e A171170 .41..41..41..41.
%e A171170 .341412..341412.
%e A171170 ..3412....3412..
%e A171170 ..434141414121..
%e A171170 .43234123412321.
%e A171170 .32.43414121.32.
%e A171170 ....32341232....
%e A171170 ....41432141....
%e A171170 .41.34323212.41.
%e A171170 .34143214321412.
%e A171170 ..343232323212..
%e A171170 ..4321....4321..
%e A171170 .432321..432321.
%e A171170 .32..32..32..32.
%e A171170 ================
%e A171170 (End)
%Y A171170 Cf. A139250, A139251, A160410, A161411, A171171.
%K A171170 nonn,tabf
%O A171170 1,2
%A A171170 _Omar E. Pol_, Dec 04 2009