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 A168113 First differences of A168112. 3
 1, 1, 2, 3, 3, 3, 6, 7, 6, 3, 6, 7, 8, 9, 16, 17, 10, 3, 6, 7, 8, 9, 16, 17, 12, 9, 16, 19, 22, 31, 46, 41, 18, 3, 6, 7, 8, 9, 16, 17, 12, 9, 16, 19, 22, 31, 46, 41, 20, 9, 16, 19, 22, 31, 46, 43, 30, 31, 48 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(n) is the number of toothpicks added at the n-th round in the toothpick structure of A168112. 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 Observation: It appears that a(2^i+2) = 3, for i>0. a(n) = A160731(n)/2. [From Nathaniel Johnston, Mar 28 2011] EXAMPLE If written as a triangle, begins: 1; 1; 2; 3,3; 3,6,7,6; 3,6,7,8,9,16,17,10; 3,6,7,8,9,16,17,12,9,16,19,22,31,46,41,18; Rows converge to A168114. CROSSREFS Cf. A139250, A139251, A152978, A152980, A160407, A168112, A168114. Sequence in context: A245642 A289559 A070167 * A170895 A141479 A055081 Adjacent sequences:  A168110 A168111 A168112 * A168114 A168115 A168116 KEYWORD nonn,tabf AUTHOR Omar E. Pol, Dec 07 2009 EXTENSIONS Terms after a(34) from Nathaniel Johnston, Mar 28 2011 STATUS approved

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Last modified May 18 23:56 EDT 2021. Contains 344009 sequences. (Running on oeis4.)