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 A323651 Number of elements added at n-th stage to the toothpick structure of A323650. 8
 1, 2, 4, 8, 4, 8, 12, 24, 4, 8, 12, 24, 12, 24, 36, 72, 4, 8, 12, 24, 12, 24, 36, 72, 12, 24, 36, 72, 36, 72, 108, 216, 4, 8, 12, 24, 12, 24, 36, 72, 12, 24, 36, 72, 36, 72, 108, 216, 12, 24, 36, 72, 36, 72, 108, 216, 36, 72, 108, 216, 108, 216, 324, 648, 4, 8, 12, 24, 12, 24, 36, 72, 12, 24, 36, 72, 36, 72, 108, 216 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The odd-indexed terms (a bisection) gives A147582, the first differences of A147562 (Ulam-Warburton cellular automaton). The even-indexed terms (a bisection) gives A147582 multiplied by 2. The word of this cellular automaton is "ab", so the structure of the irregular triangle is as shown below: a,b; a,b; a,b,a,b; a,b,a,b,a,b,a,b; a,b,a,b,a,b,a,b,a,b,a,b,a,b,a,b; ... Row lengths are the terms of A011782 multiplied by 2, also the column 2 of A296612. Columns "a" contain numbers of I-toothpicks. Columns "b" contain numbers of V-toothpicks. See the example. For further information about the word of cellular automata see A296612. LINKS N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS FORMULA a(2n-1) = A147582(n). a(2n) = 2*A147582(n). a(n) = 4*A323641(n-2), n >= 3. EXAMPLE Written as an irregular triangle the sequence begins: 1,2; 4,8; 4,8,12,24; 4,8,12,24,12,24,36,72; 4,8,12,24,12,24,36,72,12,24,36,72,36,72,108,216; 4,8,12,24,12,24,36,72,12,24,36,72,36,72,108,216,12,24,36,72,36,72,108,216,... ... CROSSREFS First differences of A323650. Cf. A011782, A139250, A139251, A147562, A147582, A160120, A160121, A161206, A161207, A296612, A323641, A323642, A323649. For other hybrid cellular automata, see A194701, A194271, A220501, A290221, A294021, A294981. Sequence in context: A191333 A078479 A060968 * A151569 A016635 A133992 Adjacent sequences:  A323648 A323649 A323650 * A323652 A323653 A323654 KEYWORD nonn AUTHOR Omar E. Pol, Feb 04 2019 STATUS approved

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Last modified April 15 10:45 EDT 2021. Contains 342977 sequences. (Running on oeis4.)