This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A220499 Number of line segments in an H tree with n levels that have no correspondence with the toothpicks of the toothpick structure of A139250 after n-th stage. 0
 0, 0, 0, 0, 4, 16, 40, 92, 212, 464, 968, 1980, 4016, 8096, 16260, 32612, 65364, 130896, 261960, 524092, 1048368, 2096928, 4194052, 8388324, 16776912, 33554112, 67108516, 134217344, 268435032, 536870428, 1073741252, 2147482996, 4294966612, 8589933904 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS More generally, differences between A000225 and A139250. LINKS David Applegate, The movie version Brian Hayes, Joshua Trees and Toothpicks Brian Hayes, The Toothpick Sequence - Bit-Player N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS Wikipedia, H tree Wikipedia, Toothpick sequence FORMULA a(n) = A000225(n) - A139250(n). EXAMPLE For n = 0..3, the number of line segments in the H tree equals the number of toothpicks in the toothpick structure of A139250, so a(n) = 0, if 0 <= n <= 3. Note that there is a correspondence between every element from the two structures. For n = 4 the H tree contains 15 line segments, on the other hand the toothpick structure contains only 11 toothpicks. There are four line segments in the H tree that have no correspondence with the toothpicks of the toothpicks structure. They are the four line segments of the last generation that are closer to the center of the H tree, so a(4) = 4. CROSSREFS Cf. A000079, A000225, A139250, A139251, A152978, A152980, A153000, A153006. Sequence in context: A152133 A297361 A210440 * A110477 A007057 A206918 Adjacent sequences:  A220496 A220497 A220498 * A220500 A220501 A220502 KEYWORD nonn AUTHOR Omar E. Pol, Feb 16 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 20 02:46 EDT 2019. Contains 322291 sequences. (Running on oeis4.)