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 A139252 Number of segments needed to draw the toothpick structure of A139250 as it is after n stages. 17
 0, 1, 3, 5, 7, 11, 15, 17, 19, 23, 27, 31, 39, 51, 59, 61, 63, 67, 71, 75, 83, 95, 103, 107, 115, 127, 139, 155, 183, 215, 231, 233, 235, 239, 243, 247, 255, 267, 275, 279, 287, 299, 311, 327, 355, 387, 403, 407, 415 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Contribution from Omar E. Pol, Sep 16 2012 (Start): It appears that A147614(n)/a(n) converge to 4. It appears that A139250(n)/a(n) converge to 3. It appears that A160124(n)/a(n) converge to 2. (End) LINKS Nathaniel Johnston, Table of n, a(n) for n = 0..256 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.] Nathaniel Johnston, C script for computing table of terms N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS EXAMPLE For n = 3, after three stages the toothpick structure of A139250 contains seven toothpicks (A139250(3) = 7), however the toothpick structure can be essentially represented by five segments, so a(3) = 5. - Omar E. Pol, Sep 16 2012 CROSSREFS Cf. A139250, A139251, A139253, A147614, A160124, A139254, A139255, A160128. Sequence in context: A082418 A319899 A085493 * A076245 A318953 A172308 Adjacent sequences:  A139249 A139250 A139251 * A139253 A139254 A139255 KEYWORD nonn AUTHOR Omar E. Pol, May 17 2008 EXTENSIONS Terms after a(28) from Nathaniel Johnston, Mar 29 2011 STATUS approved

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Last modified September 20 07:46 EDT 2020. Contains 337264 sequences. (Running on oeis4.)