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 A170842 G.f.: Product_{k>=1} (1 + 2x^(2^k-1) + 3x^(2^k)). 2
 1, 2, 3, 2, 7, 12, 9, 2, 7, 12, 13, 20, 45, 54, 27, 2, 7, 12, 13, 20, 45, 54, 31, 20, 45, 62, 79, 150, 243, 216, 81, 2, 7, 12, 13, 20, 45, 54, 31, 20, 45, 62, 79, 150, 243, 216, 85, 20, 45, 62, 79, 150, 243, 224, 133, 150, 259, 344, 537, 936, 1161, 810, 243, 2, 7, 12, 13, 20, 45 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS From Omar E. Pol, Apr 10 2021: (Start) It appears that this is also an irregular triangle read by rows (see the example). It appears that right border gives A000244. It appears that row sums give A052934. (End) LINKS John Tyler Rascoe, Table of n, a(n) for n = 0..8192 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 From Omar E. Pol, Apr 10 2021: (Start) Written as an irregular triangle in which row lengths are A000079 the sequence begins: 1; 2, 3; 2, 7, 12, 9; 2, 7, 12, 13, 20, 45, 54, 27; 2, 7, 12, 13, 20, 45, 54, 31, 20, 45, 62, 79, 150, 243, 216, 81; 2, 7, 12, 13, 20, 45, 54, 31, 20, 45, 62, 79, 150, 243, 216, 85, 20, 45, 62, ... (End) MATHEMATICA CoefficientList[Series[Product[1+2x^(2^k-1)+3x^2^k, {k, 10}], {x, 0, 70}], x] (* Harvey P. Dale, Apr 09 2021 *) PROG (PARI) D_x(N) = {my( x='x+O('x^N)); Vec(prod(k=1, logint(N, 2)+1, (1+2*x^(2^k-1)+3*x^(2^k))))} D_x((2^6)+1) \\ John Tyler Rascoe, Aug 16 2024 CROSSREFS Cf. A000079, A000244, A052934, A275667. Sequence in context: A209774 A271322 A373420 * A014784 A048601 A008317 Adjacent sequences: A170839 A170840 A170841 * A170843 A170844 A170845 KEYWORD nonn,tabf AUTHOR N. J. A. Sloane, Jan 02 2010 STATUS approved

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Last modified September 14 13:32 EDT 2024. Contains 375921 sequences. (Running on oeis4.)