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A171170 Corner sequence (starting each round in the first quadrant). 1
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, 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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
See A161411, which is the main entry for this sequence.
See also A171171 for another version.
LINKS
David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, 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.]
EXAMPLE
================
.......41.......
.......32.......
================
......4141......
......3..2......
......4..1......
......3232......
================
.....41..41.....
.....3....2.....
................
................
.....4....1.....
.....32..32.....
================
....41414141....
....3..23..2....
....4......1....
....32....32....
....41....41....
....3......2....
....4..14..1....
....32323232....
================
...41......41...
...3........2...
................
................
................
................
................
................
................
...4........1...
...32......32...
================
And so on.
Triangle begins:
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;
3,4,1,4,1,2,1,2,3, 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, 1,2,3, 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, 2,3,4,3,4,1,4,1,2;
Contribution from Omar E. Pol, Dec 09 2009: (Start)
Illustration for n = 1..148
================
.41..41..41..41.
.341412..341412.
..3412....3412..
..434141414121..
.43234123412321.
.32.43414121.32.
....32341232....
....41432141....
.41.34323212.41.
.34143214321412.
..343232323212..
..4321....4321..
.432321..432321.
.32..32..32..32.
================
(End)
CROSSREFS
Sequence in context: A134581 A099587 A172160 * A256913 A346617 A160386
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Dec 04 2009
STATUS
approved

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Last modified May 20 10:58 EDT 2024. Contains 372712 sequences. (Running on oeis4.)