

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 nth 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

Table of n, a(n) for n=0..33.
David Applegate, The movie version
Brian Hayes, Joshua Trees and Toothpicks
Brian Hayes, The Toothpick Sequence  BitPlayer
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



