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A220524 D-toothpick sequence of the third kind in the first quadrant. 7
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 (list; graph; refs; listen; history; text; internal format)
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 like-fractal) behavior. For more information see A194700.

First differs from A194444 at a(13).

LINKS

Table of n, a(n) for n=0..51.

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to toothpick sequences

FORMULA

a(n) = A220514(n)/4. - Omar E. Pol, Mar 23 2013

CROSSREFS

Cf. A139250, A194270, A194700, A194444, A220500, A220514, A220520, A220525.

Sequence in context: A327330 A231348 A194444 * A169626 A160808 A151567

Adjacent sequences:  A220521 A220522 A220523 * A220525 A220526 A220527

KEYWORD

nonn

AUTHOR

Omar E. Pol, Dec 15 2012

STATUS

approved

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Last modified December 8 12:24 EST 2019. Contains 329862 sequences. (Running on oeis4.)