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 A139560 Number of new segments added to the toothpick structure drawing at the n-th step (extensions of earlier segments are not considered). 6
 1, 2, 2, 2, 4, 4, 2, 2, 4, 4, 4, 8, 12, 8, 2, 2, 4, 4, 4, 8, 12, 8, 4, 8, 12, 12, 16, 28, 32, 16, 2, 2, 4, 4, 4, 8, 12, 8, 4, 8, 12, 12, 16, 28, 32, 16, 4, 8, 12, 12, 16, 28, 32, 20, 16, 28, 36, 40, 60, 88, 80, 32 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS First differences of A139252. 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.] N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS FORMULA a(n)=A139252(n)-A139252(n-1). CROSSREFS Cf. A139250, A139251, A139252, A139253, A139254, A139559. Sequence in context: A071472 A064135 A179651 * A192095 A105080 A206424 Adjacent sequences:  A139557 A139558 A139559 * A139561 A139562 A139563 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 January 18 23:05 EST 2019. Contains 319282 sequences. (Running on oeis4.)