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A220524
D-toothpick sequence of the third kind in the first quadrant.
8
0, 1, 3, 7, 11, 15, 23, 34, 42, 46, 54, 70, 94, 110, 130, 155, 171, 175, 183, 199, 223, 255, 291, 333, 377, 397, 421, 465, 529, 569, 613, 666, 698, 702, 710, 726, 750, 782, 818, 862, 914, 956, 1004, 1068, 1168, 1248, 1332, 1423, 1507, 1535, 1559, 1607
OFFSET
0,3
COMMENTS
This is a toothpick sequence of forking paths to 135 degrees in the first quadrant. The sequence gives the number of toothpicks and D-toothpicks in the structure after n-th stage. A220525 (the first differences) give the number of toothpicks or D-toothpicks added at n-th stage. It appears that the structure has a fractal (or fractal-like) behavior. For more information see A194700.
First differs from A194444 at a(13).
FORMULA
a(n) = A220514(n)/4. - Omar E. Pol, Mar 23 2013
KEYWORD
nonn
AUTHOR
Omar E. Pol, Dec 15 2012
STATUS
approved