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 A173531 a(0)=0: For n>0, a(n) = A060632(n)*A060632(n-1). 2
 0, 1, 2, 4, 4, 4, 8, 16, 8, 4, 8, 16, 16, 16, 32, 64, 16, 4, 8, 16, 16, 16, 32, 64, 32, 16, 32, 64, 64, 64, 128, 256, 32, 4, 8, 16, 16, 16, 32, 64, 32, 16, 32, 64, 64, 64, 128, 256, 64, 16, 32, 64, 64, 64, 128, 256, 128, 64, 128, 256, 256 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS First differences of A173530. Number of triangles (Or V-toothpicks, or L-toothpicks, etc.) added in the three-dimensional structure of A173530 at the n-th stage. 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 EXAMPLE If written as a triangle, begins: 0; 1; 2; 4,4; 4,8,16,8; 4,8,16,16,16,32,64,16; 4,8,16,16,16,32,64,32,16,32,64,64,64,128,256,32; 4,8,16,16,16,32,64,32,16,32,64,64,64,128,256,64,16,32,64,64,64,128,256,128,... CROSSREFS Cf. A001316, A047999, A060632, A139250, A139251, A161207, A172311, A173530, A173532. Sequence in context: A139251 A182635 A188346 * A122788 A078003 A081524 Adjacent sequences:  A173528 A173529 A173530 * A173532 A173533 A173534 KEYWORD nonn AUTHOR Omar E. Pol, Oct 10 2010 STATUS approved

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Last modified December 19 10:10 EST 2018. Contains 318246 sequences. (Running on oeis4.)